JPH10332718A - Scanning type probe microscope - Google Patents
Scanning type probe microscopeInfo
- Publication number
- JPH10332718A JPH10332718A JP14491297A JP14491297A JPH10332718A JP H10332718 A JPH10332718 A JP H10332718A JP 14491297 A JP14491297 A JP 14491297A JP 14491297 A JP14491297 A JP 14491297A JP H10332718 A JPH10332718 A JP H10332718A
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- Prior art keywords
- sample
- probe
- magnetic
- magnetization
- magnetic material
- Prior art date
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Abstract
Description
【０００１】[0001]
【発明の属する技術分野】本発明は、走査型プローブ顕
微鏡に関わり、特に表面の磁気的性質を調べるように改
良した走査型プローブ顕微鏡に関する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a scanning probe microscope, and more particularly to a scanning probe microscope improved to examine the magnetic properties of a surface.
【０００２】[0002]
【従来の技術】走査型プローブ顕微鏡による試料表面の
磁気的性質を調べる方法には従来、探針に磁性体を用い
て試料と探針の間に働く磁気力を検知することで表面か
らの漏れ磁場の測定を行う磁気力顕微鏡があり、アプラ
イド・フィジックス・レターズ（Applied Physics Lett
ers）50巻（1987年）1455頁から1457頁に報告されてい
る。2. Description of the Related Art Conventionally, a method of examining the magnetic properties of a sample surface using a scanning probe microscope has been known in which a magnetic material is used as a probe to detect a magnetic force acting between the sample and the probe. There is a magnetic force microscope that measures the magnetic field. Applied Physics Lett
ers), vol. 50 (1987), pp. 1455--1457.
【０００３】[0003]
【発明が解決しようとする課題】しかし、上記方法は、
磁性探針を直接、試料表面すれすれに近付けることを必
要とするため、磁性探針からの漏れ磁場で試料表面の磁
気的な性質を乱すという欠点があった。However, the above method is
Since it is necessary to bring the magnetic probe directly close to the sample surface, there is a drawback that the magnetic properties of the sample surface are disturbed by the leakage magnetic field from the magnetic probe.
【０００４】また、上記方法は、試料表面の磁気的な性
質を調べるために、磁性探針と試料との間に働く磁気力
を検知することを利用しているが、この磁気力は微少な
力であるため、その力を検出するために特殊な装置（例
えば、探針位置の微少変位を検出する光てこ装置）を必
要とする。そのため、装置全体が大型化および複雑化
し、これによって装置の取扱が困難になる欠点および装
置全体の価格が高価になる欠点があった。Further, the above-mentioned method utilizes the detection of a magnetic force acting between a magnetic probe and a sample in order to examine the magnetic properties of the sample surface. Since the force is a force, a special device (for example, an optical lever device for detecting a minute displacement of the probe position) is required to detect the force. As a result, the entire apparatus becomes larger and more complicated, which makes it difficult to handle the apparatus and increases the price of the entire apparatus.
【０００５】さらに、上記方法は、試料表面からの漏れ
磁場を磁性探針が検出することにより試料表面の磁気的
な性質を測定するため、試料表面内において漏れ磁場が
ないような場所の磁気的な性質は測定できないという欠
点があった。Further, in the above method, the magnetic property of the sample surface is measured by detecting the magnetic field leaking from the sample surface with a magnetic probe. However, there was a drawback that such properties could not be measured.
【０００６】本発明が解決しようとする課題は、安価で
構造が単純かつコンパクトな装置を用いて、試料表面の
任意の場所の磁気的な性質を磁化状態を乱すことなく高
分解能で測定することにある。An object of the present invention is to measure a magnetic property at an arbitrary position on a sample surface at a high resolution without disturbing a magnetization state using an inexpensive, simple and compact apparatus. It is in.
【０００７】[0007]
【課題を解決するための手段】上記の問題点は、導電性
の磁性体探針の先端に伝導電子のスピン反転距離よりも
薄い導電性の非磁性体層を形成することで解決できる。
ここでスピン反転距離とは、電子が物質中を伝播する際
に、スピンが反転せずに進む平均距離である。The above problems can be solved by forming a conductive non-magnetic layer thinner than the spin inversion distance of the conduction electrons at the tip of the conductive magnetic probe.
Here, the spin inversion distance is an average distance in which the spin travels without being inverted when an electron propagates through a substance.
【０００８】ここで本発明の元となる現象について説明
する。図１に示すように、磁性体11／非磁性体12／磁性
体13の３層膜を考える。ここで、磁性体は共に単磁区で
磁化方向は面内とする。この３層膜において、磁性体11
と非磁性体12との間に直流電源14で電圧を印加して非磁
性体12から磁性体11へ電流Ｉを流すと、磁性体11中の偏
極電子は磁性体11と非磁性体12の界面を通って非磁性体
12へと流れ込む。この時、非磁性体12と磁性体13との間
の電位差Ｖが、磁性体11の磁化15と磁性体13の磁化16と
の相対方向に依存して変化する。今、非磁性体12を接地
電位とすると、磁性体11と磁性体13の磁化の向きが平行
の場合には電圧計17で測定した磁性体13の電位は正とな
り、磁性体11と磁性体13の磁化の向きが反平行の場合に
は磁性体13の電位は負となる。なおこの場合、試料の厚
さに関しては、非磁性体12の厚さｄが、磁性体11から流
れ込んだ偏極電子のスピン反転距離程度もしくはそれ以
下であればよく、他の磁性体の厚さには特に制限はな
い。この非磁性体12と磁性体13の間の電位差が磁性体11
の磁化15と磁性体13の磁化16との相対方向の関数として
変化する現象は、サイエンス（Science）260巻（1993
年）320頁から323頁に解説されている。この時、非磁性
体12と磁性体13は電気的に接触している必要はなく、磁
性体11から非磁性体12に偏極電子が流れ込むことで、非
磁性体12と磁性体13の間に電位差が生じる。これは、両
者の間の電位差が非磁性体12と磁性体13の中の電子状態
で決まるため、それらの間隔には依存しないことによ
る。Here, the phenomena underlying the present invention will be described. As shown in FIG. 1, a three-layer film of a magnetic body 11, a non-magnetic body 12, and a magnetic body 13 is considered. Here, the magnetic body is a single magnetic domain and the magnetization direction is in-plane. In this three-layer film, the magnetic material 11
When a current is applied from the non-magnetic material 12 to the magnetic material 11 by applying a voltage between the non-magnetic material 12 and the DC power source 14, the polarized electrons in the magnetic material 11 Non-magnetic material through the interface of
Flows into 12. At this time, the potential difference V between the non-magnetic body 12 and the magnetic body 13 changes depending on the relative direction between the magnetization 15 of the magnetic body 11 and the magnetization 16 of the magnetic body 13. When the nonmagnetic material 12 is set to the ground potential, when the magnetization directions of the magnetic material 11 and the magnetic material 13 are parallel, the potential of the magnetic material 13 measured by the voltmeter 17 becomes positive, and the magnetic material 11 and the magnetic material When the magnetization directions of 13 are antiparallel, the potential of the magnetic body 13 becomes negative. In this case, regarding the thickness of the sample, the thickness d of the nonmagnetic material 12 may be about the spin reversal distance of the polarized electrons flowing from the magnetic material 11 or less, and the thickness of the other magnetic material Is not particularly limited. The potential difference between the non-magnetic material 12 and the magnetic material 13 is
The phenomenon that changes as a function of the relative direction between the magnetization 15 of the magnetic material 13 and the magnetization 16 of the magnetic material 13 is described in Science, Vol. 260 (1993).
It is explained from page 320 to page 323. At this time, the non-magnetic body 12 and the magnetic body 13 do not need to be in electrical contact with each other, and the polarized electrons flow from the magnetic body 11 to the non-magnetic body 12, so that the non-magnetic body 12 and the magnetic body 13 Generates a potential difference. This is because the potential difference between the two is determined by the electronic state in the non-magnetic body 12 and the magnetic body 13 and therefore does not depend on the distance between them.
【０００９】従って、走査型プローブ顕微鏡において、
スピン反転距離程度の薄さの非磁性体で被覆した磁性体
探針を用い、これを磁性体試料に近付ければ、両者が接
触していなくても探針表面の非磁性層と試料間の電位差
は上記原理により探針の磁性体部分の磁化と試料の磁化
との相対方向に依存して変化する。この時あらかじめ探
針の磁性体部分の磁化を一方向にそろえておけば、探針
表面の非磁性層と試料間の電位差の変化を測定すること
により、試料の磁化方向が特定できることになる。Therefore, in a scanning probe microscope,
Using a magnetic probe covered with a non-magnetic material with a thickness as small as the spin inversion distance, and bringing it close to the magnetic material sample, the contact between the non-magnetic layer on the probe surface and the sample can be obtained even if they are not in contact with each other. The potential difference changes depending on the relative direction between the magnetization of the magnetic part of the probe and the magnetization of the sample according to the above principle. At this time, if the magnetization of the magnetic portion of the probe is previously aligned in one direction, the magnetization direction of the sample can be specified by measuring the change in the potential difference between the nonmagnetic layer on the surface of the probe and the sample.
【００１０】[0010]
【発明の実施の形態】図２は本発明による走査型プロー
ブ顕微鏡の実施例の第一の基本構成を示す図である。本
構成は試料21、探針22、直流電源14、電圧計17からな
る。ここで探針22は磁性体23と非磁性体24からなる。非
磁性体24は通常の走査プローブ顕微鏡に使われているも
のと同じように先鋭化した形状のものを用いるが、その
長さｄはスピン反転距離程度かそれ以下とする。この場
合、スピン反転距離は非磁性体の材料によって異なる。
例えば、非磁性金属であるAuの場合、およそ5nmであ
り、非磁性半導体であるGaAsでは1000nm程度である。従
って用途に応じて材料を選べば良い。また直流電源14は
磁性体23と非磁性体24との間に接続することで電流が非
磁性体24から磁性体23へ流れるようにし、電圧計17は非
磁性体23と試料21との間に接続するものとする。FIG. 2 is a diagram showing a first basic configuration of an embodiment of the scanning probe microscope according to the present invention. This configuration includes a sample 21, a probe 22, a DC power supply 14, and a voltmeter 17. Here, the probe 22 includes a magnetic body 23 and a non-magnetic body 24. The non-magnetic material 24 has a sharpened shape like the one used in a normal scanning probe microscope, and the length d is set to be about the spin inversion distance or less. In this case, the spin inversion distance differs depending on the material of the nonmagnetic material.
For example, in the case of Au which is a non-magnetic metal, it is about 5 nm, and in the case of GaAs which is a non-magnetic semiconductor, it is about 1000 nm. Therefore, the material may be selected according to the application. The DC power supply 14 is connected between the magnetic substance 23 and the non-magnetic substance 24 so that current flows from the non-magnetic substance 24 to the magnetic substance 23, and the voltmeter 17 is connected between the non-magnetic substance 23 and the sample 21. Shall be connected to
【００１１】この構成では、探針22を試料21に近付けた
時、電圧計17によって測定される電圧Ｖは、試料の磁化
25と探針の磁化26の相対方向によって変化する。この
時、あらかじめ探針22の磁性体23部分の磁化26を試料21
表面と平行になるように形状異方性などにより容易軸を
決め固定しておくことにより、試料21の面内の磁化25が
測定できる。従って、電圧Ｖを測定しながら探針22を試
料21上で走査することで、試料21表面の面内磁化成分の
分布を知ることができる。さらに、従来の磁気力顕微鏡
と同様に探針22の先端を試料21に充分近付けて測定する
ことにより、試料21面内の磁化分布を高分解能で測定す
ることが可能となる。In this configuration, when the probe 22 is brought close to the sample 21, the voltage V measured by the voltmeter 17 is equal to the magnetization of the sample.
It changes depending on the relative direction of 25 and the magnetization 26 of the probe. At this time, the magnetization 26 of the magnetic body 23
The in-plane magnetization 25 of the sample 21 can be measured by determining and fixing an easy axis based on shape anisotropy or the like so as to be parallel to the surface. Therefore, by scanning the probe 22 on the sample 21 while measuring the voltage V, the distribution of the in-plane magnetization component on the surface of the sample 21 can be known. Further, by measuring the tip of the probe 22 sufficiently close to the sample 21 as in the conventional magnetic force microscope, the magnetization distribution in the surface of the sample 21 can be measured with high resolution.
【００１２】さらに、本発明において探針は図３に示す
ように、磁性体23と非磁性体31がつながった線材におい
て、非磁性体31を化学研磨等によって先鋭化する（非磁
性体24）ことにより作ればよい。ここで先鋭化した非磁
性体24の長さは、非磁性体24に対するスピン反転距離程
度かそれ以下とする。Further, in the present invention, as shown in FIG. 3, in the probe, the non-magnetic material 31 is sharpened by chemical polishing or the like in the wire rod in which the magnetic material 23 and the non-magnetic material 31 are connected (non-magnetic material 24). You can make it by doing. Here, the length of the sharpened non-magnetic material 24 is set to be equal to or shorter than the spin inversion distance with respect to the non-magnetic material 24.
【００１３】さらに、本発明において探針は図４に示す
ように、あらかじめ先鋭化した磁性体41の表面に厚さｄ
の非磁性体32を蒸着またはめっきなどにより被覆するこ
とによって作ってもよい。ここで被覆する非磁性体42の
厚さは、非磁性体42に対するスピン反転距離程度かそれ
以下とする。Further, in the present invention, as shown in FIG. 4, the probe has a thickness d on the surface of the magnetic material 41 which has been sharpened in advance.
May be formed by coating the non-magnetic material 32 by vapor deposition or plating. Here, the thickness of the nonmagnetic material 42 to be coated is set to be about the spin reversal distance with respect to the nonmagnetic material 42 or less.
【００１４】図５は、本発明による走査型プローブ顕微
鏡において探針の磁性体部分の磁化を一方向にそろえる
ための基本構成を示す図である。本構成は、探針先端部
分である非磁性体24、額縁状の磁性体51、およびこの額
縁状の磁性体51の一部に巻き付けた電磁コイル52からな
る。FIG. 5 is a diagram showing a basic configuration for aligning the magnetization of the magnetic portion of the probe in one direction in the scanning probe microscope according to the present invention. This configuration includes a non-magnetic body 24 which is a tip portion of a probe, a frame-shaped magnetic body 51, and an electromagnetic coil 52 wound around a part of the frame-shaped magnetic body 51.
【００１５】この構成では、電磁コイル52に直流電流を
流すことで磁性体51の磁化53を周回方向にそろえること
が可能となる。なお、この構成では、非磁性体24が接触
している磁性体51部分の磁化53の方向は、非磁性体24の
長さ方向に対して垂直であるから、第一の実施例に示し
た試料21面内の磁化25を測定する探針22が提供されるこ
とになる。In this configuration, by passing a DC current through the electromagnetic coil 52, the magnetization 53 of the magnetic body 51 can be aligned in the circumferential direction. In this configuration, the direction of the magnetization 53 of the portion of the magnetic body 51 with which the non-magnetic body 24 is in contact is perpendicular to the length direction of the non-magnetic body 24, and thus is shown in the first embodiment. A probe 22 for measuring the magnetization 25 in the plane of the sample 21 will be provided.
【００１６】さらに、この構成では、磁性体51が額縁状
の形状であるため、探針からの漏れ磁場はほとんどない
ため、探針を試料に近付けても漏れ磁場によって試料の
磁化状態が乱されることはない。Further, in this configuration, since the magnetic body 51 has a frame shape, there is almost no leakage magnetic field from the probe. Therefore, even when the probe is brought close to the sample, the magnetization state of the sample is disturbed by the leakage magnetic field. Never.
【００１７】さらに、本構成において探針の磁性体51部
分の磁化53は電磁コイル52を用いて一方向にそろえた
が、磁性体51の形状異方性などによってあらかじめ一方
向にそろえることで、電磁コイル52は不要となり、構成
はさらに簡略化できる。Further, in the present configuration, the magnetization 53 of the magnetic body 51 of the probe is aligned in one direction by using the electromagnetic coil 52. However, the magnetization 53 is aligned in one direction in advance due to the shape anisotropy of the magnetic body 51. The electromagnetic coil 52 becomes unnecessary, and the configuration can be further simplified.
【００１８】図６は本発明による走査型プローブ顕微鏡
の実施例の第二の基本構成を示す図である。本構成は試
料61、探針62、直流電源14、電圧計17からなる。ここで
探針62は磁性体63、非磁性体24および磁性体63に巻き付
けた電磁コイル64からなる。非磁性体24は通常の走査プ
ローブ顕微鏡に使われているものと同じように先鋭化し
た形状のものを用いるが、その長さはスピン反転距離程
度かそれ以下とする。また直流電源14は磁性体63と非磁
性体24との間に接続し、電圧計17は非磁性体24と試料61
との間に接続するものとする。FIG. 6 is a diagram showing a second basic configuration of an embodiment of the scanning probe microscope according to the present invention. This configuration includes a sample 61, a probe 62, a DC power supply 14, and a voltmeter 17. Here, the probe 62 includes a magnetic body 63, a non-magnetic body 24, and an electromagnetic coil 64 wound around the magnetic body 63. The non-magnetic body 24 has a sharpened shape like the one used in a normal scanning probe microscope, and its length is set to be about the spin inversion distance or less. The DC power supply 14 is connected between the magnetic body 63 and the non-magnetic body 24, and the voltmeter 17 is connected to the non-magnetic body 24 and the sample 61.
And between them.
【００１９】この構成では、探針62を試料61に近付けた
時、電圧計17によって測定される電圧Ｖは、試料61の磁
化65と探針62の磁性体63部分の磁化66の相対方向によっ
て変化する。この時、あらかじめ探針62の磁性体63部分
の磁化66を試料61表面と垂直になるように容易軸を決
め、固定しておくことにより、試料61表面に対して垂直
な磁化65が測定できる。ここで探針62の磁性体63部分の
磁化66は電磁コイル64を用いて一方向にそろえれば良
い。従って、電圧Ｖを測定しながら探針62を試料61上で
走査することで、試料61表面の垂直磁化成分の分布を知
ることができる。さらに、探針62の先端を試料61に充分
近付けて測定することにより第一の実施例と同様に、試
料61表面の磁化分布を高分解能で測定することが可能と
なる。In this configuration, when the probe 62 is brought close to the sample 61, the voltage V measured by the voltmeter 17 depends on the relative direction of the magnetization 65 of the sample 61 and the magnetization 66 of the magnetic body 63 of the probe 62. Change. At this time, the magnetization 66 of the magnetic body 63 of the probe 62 is determined in advance so that the easy axis is perpendicular to the surface of the sample 61 and fixed, so that the magnetization 65 perpendicular to the surface of the sample 61 can be measured. . Here, the magnetization 66 of the magnetic body 63 of the probe 62 may be aligned in one direction using the electromagnetic coil 64. Therefore, by scanning the probe 62 on the sample 61 while measuring the voltage V, the distribution of the perpendicular magnetization component on the surface of the sample 61 can be known. Further, by measuring the tip of the probe 62 sufficiently close to the sample 61, the magnetization distribution on the surface of the sample 61 can be measured with high resolution, as in the first embodiment.
【００２０】さらに、本構成において探針62は、第一の
実施例と同様に、化学研磨もしくは蒸着などの方法によ
り作ればよい。Further, in this configuration, the probe 62 may be made by a method such as chemical polishing or vapor deposition as in the first embodiment.
【００２１】さらに、この構成では、磁性体63先端から
磁場が漏れていると考えられるが、磁性体63と試料61の
間には非磁性体24が存在するため、通常の磁気力顕微鏡
のように磁性探針を直接試料に近付ける場合と比べて、
漏れ磁場による試料の磁化状態の乱れは小さいと考えら
れる。Further, in this configuration, it is considered that the magnetic field is leaking from the tip of the magnetic body 63, but since the non-magnetic body 24 exists between the magnetic body 63 and the sample 61, the magnetic field is different from that of a normal magnetic force microscope. In comparison with the case where the magnetic probe is brought close to the sample directly,
It is considered that the disturbance of the magnetization state of the sample due to the leakage magnetic field is small.
【００２２】さらに、本構成において探針62の磁性体63
部分の磁化66は電磁コイル64を用いて一方向にそろえた
が、磁性体63の形状異方性などによってあらかじめ一方
向にそろえることで、電磁コイル64は不要となり、構成
はさらに簡略化できる。Further, in this configuration, the magnetic body 63 of the probe 62
Although the magnetization 66 of the portion is aligned in one direction by using the electromagnetic coil 64, the alignment is previously aligned in one direction due to the shape anisotropy of the magnetic body 63, so that the electromagnetic coil 64 becomes unnecessary and the configuration can be further simplified.
【００２３】図７は本発明による走査型プローブ顕微鏡
の実施例の第三の基本構成を示す図である。本構成は試
料21、探針71、探針走査用ピエゾ駆動系72、直流電源1
4、電圧計17、電磁コイル52、電源73、発振器74、ロッ
クイン・アンプ75、プリアンプ76、およびこれら装置の
制御とデータ収集を行うためのコンピュータ77からな
る。さらに探針71は図５で説明した額縁状の磁性体51お
よび先鋭化した非磁性体24からなる。ここで、非磁性体
24の長さは第一の実施例と同様に、スピン反転距離程度
かそれ以下とする。また直流電源14は磁性体51と非磁性
体24との間に接続することで電流が非磁性体24から磁性
体51へ流れるようにし、電圧計17は非磁性体24と試料21
との間に接続するものとする。さらに、電磁コイル52は
額縁状の磁性体51の一部に巻き付け、電源73により電磁
コイル52に電流を流すことで磁性体51の磁化を周回方向
にそろえるものとする。この時、電流を流す方向を反転
することで、磁性体51の磁化方向を反転できる。FIG. 7 is a diagram showing a third basic configuration of an embodiment of the scanning probe microscope according to the present invention. This configuration consists of a sample 21, a probe 71, a piezo drive system 72 for probe scanning, and a DC power supply 1
4. Consists of a voltmeter 17, an electromagnetic coil 52, a power supply 73, an oscillator 74, a lock-in amplifier 75, a preamplifier 76, and a computer 77 for controlling these devices and collecting data. Further, the probe 71 is composed of the frame-shaped magnetic body 51 and the sharpened non-magnetic body 24 described with reference to FIG. Where the non-magnetic material
The length of 24 is about the spin inversion distance or less, as in the first embodiment. The DC power supply 14 is connected between the magnetic body 51 and the non-magnetic body 24 so that current flows from the non-magnetic body 24 to the magnetic body 51, and the voltmeter 17 is connected to the non-magnetic body 24 and the sample 21.
And between them. Further, the electromagnetic coil 52 is wound around a part of the frame-shaped magnetic body 51, and a current is supplied to the electromagnetic coil 52 by the power supply 73 to align the magnetization of the magnetic body 51 in the circumferential direction. At this time, the magnetization direction of the magnetic body 51 can be reversed by reversing the direction in which the current flows.
【００２４】この構成では、発振器74を用いて電磁コイ
ル52に流す電流を反転させることで額縁状の磁性体51の
磁化を周波数Ｆで反転させると、非磁性体24と試料21と
の間の電位差Ｖも周波数Ｆで変化する成分を持つ。この
時、電磁コイル52に流す電流のうち周波数Ｆで変化する
成分、すなわち磁性体51の磁化反転と電位差Ｖの周波数
Ｆで変化する成分との位相差Ｐは、試料21の磁化方向に
よって変化する。従って、発振器74の出力およびプリア
ンプ76で増幅した電圧計17の出力をロックイン・アンプ
75に入力することで位相差Ｐを高精度で測定することが
できる。また電位差Ｖの周波数Ｆで変化する成分の振幅
は試料21の磁化の大きさに比例して変化する。よってこ
の位相差信号および電位差Ｖの周波数Ｆで変化する成分
の振幅をコンピュータ77によりモニタしながら探針71を
ピエゾ駆動系72により試料21上で走査することにより、
試料21表面の面内磁化成分の分布を画像化できる。さら
に装置全体をコンピュータ77によって制御することによ
り、試料21の磁化測定は自動化される。In this configuration, when the magnetization of the frame-shaped magnetic body 51 is inverted at the frequency F by inverting the current flowing through the electromagnetic coil 52 using the oscillator 74, the gap between the non-magnetic body 24 and the sample 21 is reduced. The potential difference V also has a component that changes at the frequency F. At this time, of the current flowing through the electromagnetic coil 52, the component that changes at the frequency F, that is, the phase difference P between the magnetization reversal of the magnetic body 51 and the component that changes at the frequency F of the potential difference V changes according to the magnetization direction of the sample 21. . Therefore, the output of the oscillator 74 and the output of the voltmeter 17 amplified by the preamplifier 76 are
By inputting the value to 75, the phase difference P can be measured with high accuracy. The amplitude of the component that changes at the frequency F of the potential difference V changes in proportion to the magnitude of the magnetization of the sample 21. Therefore, by scanning the probe 71 on the sample 21 by the piezo drive system 72 while monitoring the amplitude of the phase difference signal and the component of the potential difference V that changes at the frequency F by the computer 77,
The distribution of the in-plane magnetization component on the surface of the sample 21 can be imaged. Further, by controlling the entire apparatus by the computer 77, the magnetization measurement of the sample 21 is automated.
【００２５】さらに、本実施例において、探針71と試料
21の間には原子間力が働く。そこで、通常の原子間力顕
微鏡で用いられている光てこ方式等を導入することによ
り探針71と試料21間の距離を制御することができ、試料
21表面の磁化分布を高分解能で測定することが可能とな
る。Further, in this embodiment, the probe 71 and the sample
Atomic force acts between 21. Therefore, the distance between the probe 71 and the sample 21 can be controlled by introducing an optical lever method or the like used in a normal atomic force microscope.
21 It becomes possible to measure the magnetization distribution on the surface with high resolution.
【００２６】さらに本実施例において、電圧計17の代り
に電流計を取り付け、さらに試料21と探針71の間に電圧
を印加する。この構成によれば、探針71を試料21に充分
近付けた時に探針71と試料21との間にトンネル電流が流
れるため、これを電流計でモニタすることで通常の走査
型トンネル顕微鏡と同様に、探針71先端と試料21表面と
の距離を制御することができる。この時、発振器74を用
いて電磁コイル52に流す電流を周期的に反転させること
で額縁状の磁性体51の磁化を周波数Ｆで反転させると、
非磁性体24と試料21との間の電位差も周波数Ｆで変化す
る成分を持つため、両者の間に流れるトンネル電流も周
波数Ｆで変化する成分を持つ。この時、電磁コイル52に
流す電流の周波数Ｆで変化する成分、すなわち磁性体51
の磁化反転とトンネル電流の周波数Ｆで変化する成分と
の位相差Ｐは、試料21の磁化方向によって変化する。従
って、発振器74の出力および電流計の出力をロックイン
・アンプ75に入力することで位相差Ｐを測定することが
できる。またトンネル電流の周波数Ｆで変化する成分の
振幅は試料21の磁化の大きさに比例して変化する。よっ
てこの位相差信号およびトンネル電流の周波数Ｆで変化
する成分の振幅をコンピュータ77によりモニタしながら
探針71をピエゾ駆動系72により試料21上で走査すること
により、試料21表面の面内磁化成分の分布を画像化でき
る。さらに装置全体をコンピュータ77によって制御する
ことにより、試料21の磁化測定は自動化される。Further, in the present embodiment, an ammeter is attached in place of the voltmeter 17, and a voltage is applied between the sample 21 and the probe 71. According to this configuration, a tunnel current flows between the probe 71 and the sample 21 when the probe 71 is sufficiently close to the sample 21. By monitoring this with an ammeter, the same as in a normal scanning tunnel microscope. In addition, the distance between the tip of the probe 71 and the surface of the sample 21 can be controlled. At this time, when the magnetization of the frame-shaped magnetic body 51 is inverted at the frequency F by periodically inverting the current flowing through the electromagnetic coil 52 using the oscillator 74,
Since the potential difference between the nonmagnetic material 24 and the sample 21 also has a component that changes at the frequency F, the tunnel current flowing between them also has a component that changes at the frequency F. At this time, the component that changes with the frequency F of the current flowing through the electromagnetic coil 52,
The phase difference P between the magnetization reversal and the component changing at the frequency F of the tunnel current changes depending on the magnetization direction of the sample 21. Therefore, the phase difference P can be measured by inputting the output of the oscillator 74 and the output of the ammeter to the lock-in amplifier 75. The amplitude of the component that changes at the frequency F of the tunnel current changes in proportion to the magnitude of the magnetization of the sample 21. Therefore, by scanning the probe 71 on the sample 21 by the piezo drive system 72 while monitoring the amplitude of the phase difference signal and the component of the tunnel current changing at the frequency F, the in-plane magnetization component of the surface of the sample 21 is obtained. Can be imaged. Further, by controlling the entire apparatus by the computer 77, the magnetization measurement of the sample 21 is automated.
【００２７】さらに、本実施例において、探針71の代り
に第二の実施例で用いた探針62を用いることで試料21表
面に垂直な磁化成分を測定することが可能となる。Further, in this embodiment, by using the probe 62 used in the second embodiment instead of the probe 71, it is possible to measure the magnetization component perpendicular to the surface of the sample 21.
【００２８】[0028]
【発明の効果】本発明によれば、探針の先端が非磁性体
であることで、通常の磁気力顕微鏡のように磁性探針を
直接試料に近付ける場合と比べて、漏れ磁場による試料
の磁化状態の乱れは小さいという効果がある。特に、構
成によっては漏れ磁場をなくすことが可能であるため、
測定に伴う試料の磁化状態の乱れがなくなるという効果
がある。さらに本発明によれば、構成によっては試料表
面の任意の方向の磁化成分を高分解能で検出することが
できる効果がある。さらに本発明によれば、探針位置の
微少な変位を測定するための光てこが構成によっては不
要になるため、装置全体の構成が簡略化され、取り扱い
が容易になり装置全体の価格も安価となる効果がある。
これらの効果の学術分野への応用、さらにはその工業的
価値は非常に高いものである。According to the present invention, since the tip of the probe is made of a non-magnetic material, compared with a case in which the magnetic probe is directly brought close to the sample as in a normal magnetic force microscope, the sample is not affected by the leakage magnetic field. There is an effect that the disturbance of the magnetization state is small. In particular, because it is possible to eliminate the leakage magnetic field depending on the configuration,
This has the effect of eliminating the disturbance of the magnetization state of the sample due to the measurement. Further, according to the present invention, depending on the configuration, there is an effect that a magnetization component in an arbitrary direction on the sample surface can be detected with high resolution. Further, according to the present invention, an optical lever for measuring a minute displacement of the probe position is not required depending on the configuration, so that the configuration of the entire apparatus is simplified, handling is easy, and the price of the entire apparatus is low. The effect is as follows.
The application of these effects to academic fields, and their industrial value, is very high.
【図１】本発明の原理となる現象を説明する図。FIG. 1 is a diagram illustrating a phenomenon that is a principle of the present invention.
【図２】本発明の基本構成を表す図。FIG. 2 is a diagram showing a basic configuration of the present invention.
【図３】本発明で用いる探針の構成および製法を示す
図。FIG. 3 is a diagram showing a configuration and a manufacturing method of a probe used in the present invention.
【図４】本発明で用いる探針の構成および製法を示す
図。FIG. 4 is a diagram showing a configuration and a manufacturing method of a probe used in the present invention.
【図５】本発明において探針の磁性体部分の磁化を一方
向にそろえるための構成を示す図。FIG. 5 is a diagram showing a configuration for aligning the magnetization of a magnetic portion of a probe in one direction in the present invention.
【図６】本発明の第二の基本構成を示す図。FIG. 6 is a diagram showing a second basic configuration of the present invention.
【図７】本発明とコンピュータによる磁化の高精度測定
および磁化の自動制御を示す図。FIG. 7 is a diagram showing high-precision magnetization measurement and automatic magnetization control by the present invention and a computer.
11…磁性体、12…非磁性体、13…磁性体、14…直流電
源、15…磁化、16…磁化、17…電圧計、21…試料、22…
探針、23…磁性体、24…非磁性体、25…磁化、26…磁
化、31…非磁性体、41…磁性体、42…非磁性体、51…額
縁状磁性体、52…電磁コイル、53…磁化、61…試料、62
…探針、63…磁性体、64…電磁コイル、65…磁化、66…
磁化、71…探針、72…ピエゾ駆動系、73…電源、74…発
振器、75…ロックイン・アンプ、76…プリアンプ、77…
コンピュータ。11 ... magnetic material, 12 ... non-magnetic material, 13 ... magnetic material, 14 ... DC power supply, 15 ... magnetization, 16 ... magnetization, 17 ... voltmeter, 21 ... sample, 22 ...
Tip, 23: magnetic material, 24: non-magnetic material, 25: magnetization, 26: magnetization, 31: non-magnetic material, 41: magnetic material, 42: non-magnetic material, 51: frame-shaped magnetic material, 52: electromagnetic coil , 53 ... magnetization, 61 ... sample, 62
… Probe, 63… magnetic material, 64… electromagnetic coil, 65… magnetization, 66…
Magnetization, 71: Probe, 72: Piezo drive system, 73: Power supply, 74: Oscillator, 75: Lock-in amplifier, 76: Preamplifier, 77 ...
Computer.
Claims (5)
性探針と、前記導電性探針を試料の表面に近付け前記試
料と前記導電性探針との間に発生する電位差が前記試料
の表面の磁化と前記導電性探針の磁化との相対方向の関
数として変化することを検出する検出器と、を有し、前
記試料の表面の磁化状態を測定することを特徴とする走
査型プローブ顕微鏡。A conductive probe having a tip made of a non-magnetic material and made of a magnetic material; and a potential difference generated between the sample and the conductive probe when the conductive probe is brought close to the surface of the sample. A detector that detects that the magnetization of the surface of the sample and the magnetization of the conductive probe change as a function of the relative direction, and wherein the magnetization state of the surface of the sample is measured. Probe microscope.
磁性の金属を用いることを特徴とする請求項１記載の走
査型プローブ顕微鏡。2. The scanning probe microscope according to claim 1, wherein a non-magnetic metal is used for the non-magnetic material at the tip of the conductive probe.
磁性の半導体を用いることを特徴とする請求項１記載の
走査型プローブ顕微鏡。3. The scanning probe microscope according to claim 1, wherein a non-magnetic semiconductor is used for the non-magnetic material at the tip of the conductive probe.
印加する印加手段をさらに有し、前記印加手段により前
記磁性体と前記非磁性体との間に電位を印加して前記磁
性体から前記非磁性体へスピン偏極した電子を注入する
ことを特徴とする請求項１記載の走査型プローブ顕微
鏡。4. Apparatus for applying a potential between said magnetic material and said non-magnetic material, wherein said applying means applies a potential between said magnetic material and said non-magnetic material to apply said potential 2. The scanning probe microscope according to claim 1, wherein spin-polarized electrons are injected from a magnetic material into the non-magnetic material.
入された前記電子の前記非磁性体の中でのスピン反転距
離よりも薄いことを特徴とする請求項４記載の走査型プ
ローブ顕微鏡。5. The scanning type according to claim 4, wherein a thickness of said non-magnetic material is smaller than a spin inversion distance of said electrons injected from said magnetic material in said non-magnetic material. Probe microscope.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP14491297A JPH10332718A (en) | 1997-06-03 | 1997-06-03 | Scanning type probe microscope |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP14491297A JPH10332718A (en) | 1997-06-03 | 1997-06-03 | Scanning type probe microscope |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH10332718A true JPH10332718A (en) | 1998-12-18 |
Family
ID=15373164
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP14491297A Pending JPH10332718A (en) | 1997-06-03 | 1997-06-03 | Scanning type probe microscope |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH10332718A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US6655196B2 (en) | 2001-06-26 | 2003-12-02 | Hokkaido University | Scanning probe microscope |
-
1997
- 1997-06-03 JP JP14491297A patent/JPH10332718A/en active Pending
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US6655196B2 (en) | 2001-06-26 | 2003-12-02 | Hokkaido University | Scanning probe microscope |
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