CN115480288A - Image type electron spin analyzer - Google Patents
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Abstract
The invention provides an image type electron spin analyzer, which comprises a two-dimensional image type electron detector and an electron optical system, wherein the electron optical system comprises a ferromagnetic reflection target, an incident electron lens group and at least one reflection electron lens group. The invention realizes the measurement of the electron spin by utilizing different reflectivities of the ferromagnetic reflection target to electrons with different spin directions, the separation of an incident electron orbit and an emergent electron orbit can be realized by the specular reflection of the reflection target, thereby avoiding the difficulty in the geometrical configuration of an electronic optical system and an electronic detector, and enabling a lens system to adopt larger size to obtain smaller aberration, and the electronic optical system can realize the point-to-point two-dimensional imaging from an electronic image at an initial plane to an inlet plane of a two-dimensional image type electronic detector, thereby realizing the two-dimensional multi-channel measurement of the electron spin. In addition, compared with the existing image type VLEED electron spin analyzer, the image type electron spin analyzer does not need to introduce a magnetic field, and has a simpler structure.
Description
Technical Field
The invention belongs to the field of electron spin analysis, and relates to an image type electron spin analyzer.
Background
Currently, as analyzers for measuring electron Spin, mott type, spin-LEED type, and VLEED type analyzers are mainly used. The measurement mode of the Mott type analyzer is as follows: the method comprises the steps of accelerating electrons to 20-100KeV kinetic energy, scattering the electrons on a target made of a material (usually made of high atomic number elements) with high spin-orbit interaction, and measuring the spin of incident electrons by measuring the asymmetry of the intensity of the scattered electrons; spin-LEED analyzers measure the Spin of electrons by measuring the asymmetry in the intensity of the diffracted spot of an electron on the surface of a single crystal of a material with a high Spin-orbit interaction (e.g., tungsten, iridium, platinum, etc.); VLEED is a new analyzer that has been recently developed and is measured by: the electron kinetic energy is accelerated (decelerated) to 6eV, then the reflectivities of the electrons on the ferromagnetic targets magnetized in the + Z direction and the-Z direction are respectively measured, and the spin of the incident electrons in the Z direction is measured by measuring the relative difference of the two reflectivities. VLEED is the most efficient electron spin analyzer to measure at present.
Fig. 1 shows a schematic diagram of the electron spin measurement principle of a single-channel VLEED analyzer. The incident electrons at point a on the initial electron plane 11 reach the a region of the electron detector 13 by specular reflection by the reflection target 12. Similarly, the incident electrons at the point B on the initial electron plane 11 reach the B region of the electron detector 13 through a similar path. That is, each incident electron from the point a forms a larger beam spot centered on the point a on the electron detector 13, and similarly, each incident electron from the point B forms a larger beam spot centered on the point B on the electron detector 13, and the beam spot centered on the point a and the beam spot centered on the point B partially overlap due to the larger beam spots, so that the classical VLEED analyzer cannot distinguish the source position of the incident electron, that is, whether the incident electron comes from the point a or the point B. Such an electron spin analyzer that cannot distinguish the source position of the incident electrons is called a single-channel electron spin analyzer; analyzers that can distinguish the source location of incident electrons are called multi-channel analyzers or image-based analyzers. The electron spin analyzers currently in operation are almost single channel. In order to improve the efficiency of electron spin measurement, the realization of multi-channel electron spin measurement has been the focus of attention of scientific research technicians.
There are two types of multi-channel electron spin analyzers reported today. One is Spin-LEED image-type Spin analyzer created by the Kirschner research group of germany. Incident electrons of the analyzer are incident to a W (100) target at an incident angle of 45 degrees, an included angle of 90 degrees is formed between the incident electron beam and a reflected electron beam, and an imaginary image plane and an electron detector plane formed by the incident electrons on the back surface of the W (100) target are both vertical to an electron optical axis, so that an electron optical system has smaller aberration and can distinguish the source positions of the incident electrons. However, spin-LEED analyzers based on spin-orbit interactions are only one percent more efficient than VLEED analyzers based on strongly correlated interactions. In addition, since the W (100) target used in the spin-LEED analyzer cannot be magnetized, it is necessary to sequentially magnetize the sample in opposite directions, measure the reflection intensities of electrons in different magnetization directions, and determine the spin polarization of electrons emitted from the sample by the difference in the reflection intensities. Since this measurement requires magnetization of the sample, only ferromagnetic samples can be measured. The other is a VLEED type multi-channel electron spin analyzer invented by the applicant, which has been granted by Chinese patent No. 201310313572. The invention introduces the magnetic field to realize the separation of the movement tracks of the incident electrons and the emergent electrons, thereby realizing high-efficiency VLEED type multi-channel electron spin measurement, but the electron optical asymmetry of the magnetic field along the magnetic field direction and the direction vertical to the magnetic field can cause aberration, and the introduction of the magnetic field makes the structure of the whole spin analyzer complicated.
Disclosure of Invention
In view of the above-mentioned shortcomings of the prior art, the present invention is directed to an image type electron spin analyzer, which is used to solve the problems of large phase difference, complex structure, etc. of the prior art.
To achieve the above and other related objects, the present invention provides an image type electron spin analyzer, comprising:
a two-dimensional image type electronic detector;
the electron optical system comprises a ferromagnetic reflection target, an incident electron lens group and at least one reflection electron lens group, wherein the incident electron lens group is used for enabling initial incident electrons to be incident to the ferromagnetic reflection target at an incident angle theta, theta is larger than or equal to 10 degrees and smaller than 90 degrees, the ferromagnetic reflection target is used for reflecting electrons in at least two magnetization directions, and the reflection electron lens group is used for enabling the electrons reflected by the ferromagnetic reflection target to be imaged on the two-dimensional image type electronic detector.
Optionally, the ferromagnetic reflective target comprises ferromagnetic iron oxide.
Optionally, the ferromagnetic reflective target includes a substrate and a ferromagnetic iron oxide film formed on a surface of the substrate, and a material of the substrate includes magnesium oxide, aluminum magnesium oxide, or tungsten single crystal.
Optionally, the angle of incidence θ is selected from at least one of 15 °, 20 °, 25 °, 30 °, 35 °, 40 °, 45 °, 50 °, 55 °, 60 °, 70 °, 80 °, and 85 °.
Optionally, an axial angle between the incident electron lens group and the reflection electron lens group is 2 θ.
Optionally, an axial angle between the incident electron lens group and the reflection electron lens group is 90 °.
Optionally, the image type electron spin analyzer further comprises a ferromagnetic reflective target normal direction adjusting device to measure the electron spin polarization degree in different directions.
Optionally, the electron optical system comprises a first reflective electron lens group and a second reflective electron lens group; when the normal direction of the ferromagnetic reflective target is a first predetermined direction, the initial incident electrons pass through the incident electron lens set at a first incident angle θ 1 Incident to the ferromagnetic reflection target, wherein the axial included angle between the incident electronic lens group and the first reflection electronic lens group is 2 theta 1 (ii) a When the normal direction of the ferromagnetic reflective target is a second predetermined direction, the initial incident electrons pass through the incident electron lens set at a second incident angle θ 2 Incident to the ferromagnetic reflection target, wherein the axial included angle between the incident electronic lens group and the second reflection electronic lens group is 2 theta 2 。
Optionally, axes of the incident electron lens group, the first reflective electron lens group, and the second reflective electron lens group are perpendicular to each other.
Optionally, the incident electron lens group and the reflected electron lens group comprise non-axisymmetric electron lenses.
Optionally, the non-axisymmetric electron lens is an electric multi-stage lens constructed by dividing a cylindrical electric lens into a plurality of parts.
Optionally, the electric multi-stage lens is an electric four-stage lens.
Optionally, the deflection of the electron beam is achieved by adjusting an electrode voltage of the electric multi-stage lens.
Optionally, the two-dimensional image type electron detector comprises a microchannel plate, a fluorescent plate and a camera.
Optionally, the two-dimensional image type electron detector comprises a microchannel plate and a delay line detector.
Optionally, the two-dimensional image-type electron detector comprises a semiconductor detector array.
As described above, the image type electron spin analyzer of the present invention includes a two-dimensional image type electron detector and an electron optical system, wherein the electron optical system includes a ferromagnetic reflective target, an incident electron lens set, and at least one reflective electron lens set. The invention realizes the measurement of the electron spin by utilizing the different reflectivities of the ferromagnetic reflection target to the electrons with different spin directions, wherein, the ferromagnetic reflection target can realize the separation of an incident electron orbit and an emergent electron orbit, thereby avoiding the difficulty of the geometrical configuration of an electron optical system and an electron detector, and enabling a lens system to adopt larger size so as to obtain smaller aberration. The electronic optical system constructed by the ferromagnetic reflection target and the electronic lens group can realize the conversion of an imaging surface, and ensure that an object image plane is vertical to the optical axis of the electronic optical system in the two-time imaging process, thereby realizing point-to-point two-dimensional imaging from an electronic image at an initial plane to an inlet plane of a two-dimensional image type electronic detector and realizing the two-dimensional multi-channel measurement of electron spin. In addition, compared with the existing image type VLEED electron spin analyzer, the image type electron spin analyzer does not need to introduce a magnetic field, and has a simpler structure.
Drawings
Figure 1 shows a schematic diagram of electron spin measurement principle for a single channel VLEED analyzer.
Fig. 2 is a schematic structural diagram of an image type electron spin analyzer according to a first embodiment of the invention.
Fig. 3 is a schematic structural diagram of a second embodiment of the image type electron spin analyzer according to the present invention.
FIG. 4 is a schematic view of a four-level lens.
Description of the element reference numerals
11. Initial electron plane
12. Reflection target
13. Electronic detector
2. Initial electron plane
31. Incident electron lens assembly
32. Reflection electronic lens group
32' first reflection electron lens group
33. Second reflection electronic lens group
4. Ferromagnetic reflective target
51. 52 two-dimensional image type electronic detector
61. 62 imaging surface
e1 First polar plate
e2 Second pole plate
e3 Third polar plate
e4 The fourth polar plate
Detailed Description
The embodiments of the present invention are described below with reference to specific embodiments, and other advantages and effects of the present invention will be easily understood by those skilled in the art from the disclosure of the present specification. The invention is capable of other and different embodiments and of being practiced or of being carried out in various ways, and its several details are capable of modification in various respects, all without departing from the spirit and scope of the present invention.
Please refer to fig. 1 to 4. It should be noted that the drawings provided in the present embodiment are only for illustrating the basic idea of the present invention, and the components related to the present invention are only shown in the drawings rather than drawn according to the number, shape and size of the components in actual implementation, and the type, quantity and proportion of the components in actual implementation may be changed freely, and the layout of the components may be more complicated.
Example one
In this embodiment, an image-based electron spin analyzer is provided, please refer to fig. 2, which is a schematic structural diagram of the image-based electron spin analyzer, including a two-dimensional image-based electron detector 51 and an electron optical system, where the electron optical system includes a ferromagnetic reflective target 4, an incident electron lens assembly 31 and a reflective electron lens assembly 32, the incident electron lens assembly is configured to enable initial incident electrons to be incident to the ferromagnetic reflective target 4 at an incident angle θ, the ferromagnetic reflective target 4 is configured to reflect electrons in at least two magnetization directions, and the reflective electron lens assembly 32 is configured to enable electrons reflected by the ferromagnetic reflective target 4 to be imaged on the two-dimensional image-based electron detector 51.
Specifically, the two-dimensional image type electron detector 51 may be any device capable of recording an electron intensity distribution. The two-dimensional image type electron detector 51 may be constituted by a Micro-channel Plate (MCP), a fluorescent Plate, and a high-sensitivity camera, as an example. As another example, the two-dimensional image type electronic probe 51 may also be constituted by a microchannel plate and Delay Line probe (DLD) — as a third practical example, the two-dimensional image type electronic probe 51 may also include a semiconductor two-dimensional array probe.
By way of example, the ferromagnetic reflective target 4 includes, but is not limited to, ferromagnetic iron oxide. In a specific structure, the ferromagnetic reflective target 4 may include a substrate and a ferromagnetic iron oxide film formed on a surface of the substrate, where the substrate is made of, but not limited to, magnesium oxide, aluminum magnesium oxide, or tungsten single crystal. The different magnetization directions of the ferromagnetic reflective targets 4 can be realized by configuring the magnetization coil and changing the energization state of the magnetization coil.
As an example, the incident angle θ satisfies: 10 ° ≦ θ < 90 °, for example the angle of incidence θ may be selected from at least one of 15 °, 20 °, 25 °, 30 °, 35 °, 40 °, 45 °, 50 °, 55 °, 60 °, 70 °, 80 ° and 85 °.
As an example, the angle between the axes of the incident electron lens group 31 and the reflective electron lens group 32 is 2 θ.
The measurement principle of the image type electron spin analyzer of the present invention will be described below by taking the number of the reflection electron lens groups 32 as one group, the incident angle θ being 45 °, and the axial angle between the incident electron lens group 31 and the reflection electron lens group 32 being 90 °.
Specifically, as shown in fig. 2, the X-axis, the Y-axis and the Z-axis form a rectangular coordinate system, the incident electron beam moves along the Y-axis direction, the axis of the incident electron lens group 31 is along the Y-axis direction, and the axis of the reflective electron lens group 32 is along the X-axis direction. The normal direction of the reflecting target 4 is in the XY plane and forms an included angle of 45 degrees with the incident electron beam, namely the incident angle is 45 degrees. First, the ferromagnetic reflective target 4 is magnetized in the + X 'direction, wherein the X' direction is located in the XY plane, and the included angles with the X axis and the Y axis are both 45 degrees, the incident electron lens group 31 images the electrons of the initial electron plane 2 on the imaging plane 61 perpendicular to the Y axis, and after being reflected by the ferromagnetic reflective target 4, this imaging plane is converted into the imaging plane 62 perpendicular to the X axis, and the reflected electron lens group 32 images the electron intensity distribution located on the imaging plane 62 onto the entrance plane of the two-dimensional image type electronic detector 51. The high-sensitivity camera included in the two-dimensional image type electron detector 51 records a two-dimensional electron intensity image on the phosphor plate. Then, the ferromagnetic reflective target 4 is magnetized in the-X' direction, and a two-dimensional electron intensity image on the fluorescent plate is recorded again. Since the electron intensity difference of a certain pixel point in the two-dimensional electron intensity image obtained based on the two measurements is proportional to the spin polarization degree of the incident electron at the corresponding position on the initial electron plane 2 along the X 'direction, the above process can measure the spin polarization degree of the incident electron at each point on the initial electron plane 2 along the X' direction.
Similarly, by magnetizing the ferromagnetic reflective target 4 in the + Z direction and the-Z direction, respectively, the spin polarization of the incident electrons in the Z direction at each point on the initial electron plane 2 can be measured.
Similarly, by magnetizing the ferromagnetic reflective target 4 in the + Y 'direction and the-Y' direction, respectively, the spin polarization of the incident electrons in the Y 'direction, which is perpendicular to the X' direction and is located in the XY plane, at each point on the initial electron plane 2 can be measured.
The image type electron spin analyzer of the embodiment adopts a ferromagnetic reflection target as a part of an electron optical system, not only can realize the separation of an incident electron orbit and an emergent electron orbit, but also can realize the first two-dimensional imaging from an incident electron initial plane to a specific plane corresponding to the reflection target and the second two-dimensional imaging from an image plane after reflection and transfer to an inlet plane of a two-dimensional image type electron detector, and finally realize the point-to-point two-dimensional imaging from an electronic image at the initial plane of the spin detector to the inlet plane of the two-dimensional image type electron detector, thereby realizing the multi-channel measurement of electron spin. Because the object image plane is vertical to the optical axis of the electronic optical system in the two imaging processes, the real two-dimensional imaging can be ensured. Herein, the true two-dimensional imaging means that a first imaging image plane without considering aberration completely coincides with a specific plane corresponding to the reflective target, and a second imaging image plane without considering aberration completely coincides with an entrance plane of the two-dimensional image type electron detector.
Note that the efficiency of electron spin measurement is related to the energy of incident electrons, and it is not the smaller the incident angle, the higher the efficiency of electron spin measurement. In this embodiment, the 45 ° incident angle is adopted, which is convenient for the geometric configuration of the electron optical system and the electron detector, and the lens system can adopt a larger size to obtain a smaller aberration, and also has a higher electron spin measurement efficiency.
In addition, due to the processing error, the installation error and the influence of the environmental magnetic field of the electron optical system, the actual electron optical system has non-axial symmetry, and in this embodiment, it is preferable that the incident electron lens group 31 and the reflection electron lens group 32 use non-axial symmetry electric lenses, which can be used to compensate for the non-axial symmetry. The non-axisymmetric electric lens may be an electric multipole lens constructed by dividing a cylindrical lens into a plurality of cylindrical lenses, including but not limited to a quadrupole lens, a hexapole lens and an octopole lens, and the non-axisymmetric electro-optical characteristics may be adjusted by adjusting the voltages of the respective plates of the multipole lens.
As shown in fig. 4, the simplest structure of the quadrupole lens is to divide a cylindrical lens into four parts, which are respectively a first polar plate e1, a second polar plate e2, a third polar plate e3 and a fourth polar plate e4. If the first polar plate e1 and the second polar plate e2 are at the potential U12, and the third polar plate e3 and the fourth polar plate e4 are at the potential U34, the difference between the focal lengths of the quadrupole lens in the X direction and the Y direction can be adjusted by adjusting the potential difference between the potential U12 and the potential U34. Due to processing errors and mounting errors, and the influence of environmental magnetic fields, the electron beam may deviate from the electron lens axis, and a deflector needs to be added to compensate for these influences in an actual electron optical system. The multi-polar lens realizes non-axisymmetric compensation of an electron optical system, and simultaneously realizes the function of a deflector by adjusting the potential of each polar plate. Specifically, the voltage between the first polar plate e1 and the second polar plate e2 is adjusted to realize the deflection of the electron beam in the Y direction; the deflection of the electron beam in the X direction can be achieved by adjusting the voltage between the third electrode e3 and the fourth electrode e4 as well.
The image type electron spin analyzer of the present embodiment is a multichannel VLEED electron spin analyzer, which can realize separation of an incident electron orbit and an exit electron orbit by introducing a ferromagnetic reflective target, so that it is possible to increase the size of an electron lens, thereby greatly reducing aberration of the entire electron optical system. Therefore, after the incident electron beams from each position point on the initial electron plane are focused, transmitted and reflected by the electron optical system, beam spots formed at the entrance plane of the two-dimensional image type electron detector are very small and are not overlapped with each other, so that each beam spot can correspond to the incident electron beam at the corresponding position point on the initial electron plane, namely the source position of the incident electrons can be distinguished, and the multi-channel measurement of electron spin is realized.
Example two
The difference between the present embodiment and the first embodiment is that the number of the reflective electronic lens sets in the first embodiment is one group, and the number of the reflective electronic lens sets in the present embodiment isTwo groups are respectively the first reflective electronic lens group 32' and the second reflective electronic lens group 33. The image type electron spin analyzer further comprises a reflective target normal direction adjusting device (not shown) for measuring the electron spin polarization degree in different directions, wherein when the normal direction of the ferromagnetic reflective target 4 is a first predetermined direction, the initial incident electron passes through the incident electron lens assembly 31 at a first incident angle θ 1 Incident to the ferromagnetic reflective target 4, and the axial included angle between the incident electron lens group 31 and the first reflective electron lens group 32' is 2 θ 1 (ii) a When the normal direction of the ferromagnetic reflective target 4 is a second predetermined direction, the initial incident electrons pass through the incident electron lens assembly 31 at a second incident angle θ 2 Incident to the ferromagnetic reflective target 4, and the axial included angle between the incident electron lens group 31 and the second reflective electron lens group 33 is 2 θ 2 。
At a first incident angle theta 1 At a second angle of incidence theta 2 The technical solution of the present embodiment is described in 45 °, wherein the axes of the incident electron lens group 31, the first reflective electron lens group 32' and the second reflective electron lens group 33 are perpendicular to each other.
Specifically, as shown in fig. 3, the X-axis, the Y-axis and the Z-axis are perpendicular to each other, and in the electron optical system, the axis of the incident electron lens group 31 is along the X-axis, the axis of the first reflective electron lens group 32' is along the Y-axis, and the axis of the second reflective electron lens group 33 is along the Z-axis. The axis of the incident electron beam is along the X axis, the normal direction of the ferromagnetic reflective target 4 is in the XY plane and forms an included angle of 45 degrees with the incident electron beam, namely the first incident angle theta 1 At 45 degrees, the incident electron lens group 31 images the electrons of the initial electron plane 2 on an imaging plane perpendicular to the X-axis, and the imaging plane is converted into an imaging plane perpendicular to the Y-axis by the reflection of the ferromagnetic reflective target 4, and the first reflective electron lens group 32' images the electron intensity distribution of the imaging plane onto the entrance plane of the two-dimensional image type electron detector 51. The ferromagnetic reflective targets 4 are magnetized in the + Z direction and the-Z direction, respectively, and the spin polarization of the incident electrons at each point on the initial electron plane 2 in the Z direction can be measured. Same as thatThe ferromagnetic reflective targets 4 are magnetized in directions opposite to each other twice in directions forming an angle of 45 degrees with the Y axis in the XY plane, respectively, and the spin polarization of the incident electrons at each point on the initial electron plane 2 in this direction can be measured.
When the normal direction of the ferromagnetic reflective target 4 is in the XZ plane and forms a 45 degree included angle with the incident electron beam, the incident electron lens group 31 images the electrons of the initial electron plane 2 on an imaging plane perpendicular to the X axis, the imaging plane is converted into an imaging plane perpendicular to the Z axis by reflection of the ferromagnetic reflective target 4, and the second reflective electron lens group 33 images the electron intensity distribution of the imaging plane on the entrance plane of the two-dimensional image type electron detector 52. The ferromagnetic reflective targets 4 are magnetized in the + Y direction and the-Y direction, respectively, and the spin polarization of the incident electrons at each point on the initial electron plane 2 in the Y direction can be measured. Similarly, by magnetizing the ferromagnetic reflective targets 4 twice in opposite directions in the XZ plane at 45 degrees to the X axis, the spin polarization of the incident electrons in this direction at each point on the initial electron plane 2 can be measured.
Thus, by making the normal of the ferromagnetic reflective target along two different directions, the spin polarization degrees of the incident electrons along the Z and Y directions at each point on the initial electron plane 2 can be finally obtained, and the spin polarization degree of the incident electrons along the X direction at each point on the initial electron plane 2 can be solved by a simultaneous equation.
In summary, the image type electron spin analyzer of the present invention includes a two-dimensional image type electron detector and an electron optical system, wherein the electron optical system includes a ferromagnetic reflective target, an incident electron lens set and at least one reflective electron lens set. The invention realizes the measurement of the electron spin by utilizing the different reflectivities of the ferromagnetic reflection target to the electrons with different spin directions, wherein, the ferromagnetic reflection target can realize the separation of an incident electron orbit and an emergent electron orbit, thereby avoiding the difficulty of the geometrical configuration of an electron optical system and an electron detector, and enabling a lens system to adopt larger size so as to obtain smaller aberration. The electronic optical system constructed by the ferromagnetic reflecting target and the electronic lens group can realize the conversion of an imaging surface, and ensure that an object image plane is vertical to the optical axis of the electronic optical system in the two-time imaging process, thereby realizing the two-dimensional multi-channel measurement of electron spin. In addition, compared with the existing image type VLEED electron spin analyzer, the image type electron spin analyzer does not need to introduce a magnetic field, and has a simpler structure. Therefore, the invention effectively overcomes various defects in the prior art and has high industrial utilization value.
The foregoing embodiments are merely illustrative of the principles and utilities of the present invention and are not intended to limit the invention. Those skilled in the art can modify or change the above-described embodiments without departing from the spirit and scope of the present invention. Accordingly, it is intended that all equivalent modifications or changes which can be made by those skilled in the art without departing from the spirit and technical spirit of the present invention be covered by the claims of the present invention.
Claims (16)
1. An image-type electron spin analyzer, comprising:
a two-dimensional image type electronic detector;
the electron optical system comprises a ferromagnetic reflection target, an incident electron lens group and at least one reflection electron lens group, wherein the incident electron lens group is used for enabling initial incident electrons to be incident to the ferromagnetic reflection target at an incident angle theta, theta is larger than or equal to 10 degrees and smaller than 90 degrees, the ferromagnetic reflection target is used for reflecting electrons in at least two magnetization directions, and the reflection electron lens group is used for enabling the electrons reflected by the ferromagnetic reflection target to be imaged on the two-dimensional image type electronic detector.
2. The image type electron spin analyzer according to claim 1, characterized in that: the ferromagnetic reflective target is made of ferromagnetic iron oxide.
3. The image type electron spin analyzer according to claim 2, characterized in that: the ferromagnetic reflection target comprises a substrate and a ferromagnetic iron oxide film formed on the surface of the substrate, wherein the substrate is made of magnesium oxide, aluminum magnesium oxide or tungsten single crystal.
4. The image type electron spin analyzer according to claim 1, characterized in that: the incident angle θ is selected from at least one of 15 °, 20 °, 25 °, 30 °, 35 °, 40 °, 45 °, 50 °, 55 °, 60 °, 70 °, 80 °, and 85 °.
5. An image type electron spin analyzer according to claim 1, characterized in that: and the axial included angle between the incident electronic lens group and the reflection electronic lens group is 2 theta.
6. An image type electron spin analyzer according to claim 5, characterized in that: the included angle between the incident electronic lens group and the axis of the reflection electronic lens group is 90 degrees.
7. The image type electron spin analyzer according to claim 1, characterized in that: the image type electron spin analyzer also comprises a ferromagnetic reflection target normal direction adjusting device to measure the electron spin polarization degree in different directions.
8. An image type electron spin analyzer according to claim 7, characterized in that: the electron optical system comprises a first reflection electron lens group and a second reflection electron lens group; when the normal direction of the ferromagnetic reflection target is a first preset direction, the initial incident electrons pass through the incident electron lens group and are at a first incident angle theta 1 Incident to the ferromagnetic reflection target, wherein the axial included angle between the incident electronic lens group and the first reflection electronic lens group is 2 theta 1 (ii) a When the normal direction of the ferromagnetic reflection target is a second preset direction, the initial incident electrons pass through the incident electron lens group and are at a second incident angle theta 2 Incident to the ferromagnetic reflection target, wherein the axial included angle between the incident electronic lens group and the second reflection electronic lens group is 2 theta 2 。
9. An image type electron spin analyzer according to claim 8, characterized in that: the axes of the incident electronic lens group, the first reflection electronic lens group and the second reflection electronic lens group are mutually vertical.
10. The image type electron spin analyzer according to claim 1, characterized in that: the incident electron lens group and the reflected electron lens group include non-axisymmetric electron lenses.
11. An image type electron spin analyzer according to claim 10, characterized in that: the non-axisymmetric electronic lens adopts an electric multi-stage lens which is formed by a plurality of cylindrical electric lenses.
12. An image type electron spin analyzer according to claim 11, characterized in that: the electric multistage lens adopts an electric four-stage lens.
13. An image type electron spin analyzer according to claim 11, characterized in that: the deflection of the electron beam is realized by adjusting the electrode voltage of the electric multi-stage lens.
14. An image type electron spin analyzer according to claim 1, characterized in that: the two-dimensional image type electronic detector comprises a micro-channel plate, a fluorescent plate and a camera.
15. An image type electron spin analyzer according to claim 1, characterized in that: the two-dimensional image type electronic detector comprises a micro-channel plate and a delay line detector.
16. An image type electron spin analyzer according to claim 1, characterized in that: the two-dimensional image-type electron detector includes a semiconductor detector array.
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