CN102557131A

CN102557131A - Preparation method for NaV2O5

Info

Publication number: CN102557131A
Application number: CN2010105751884A
Authority: CN
Inventors: 范厚刚; 杨景海; 张永军; 王雅新; 杨丽丽; 刘洋
Original assignee: Jilin Normal University
Current assignee: Jilin Normal University
Priority date: 2010-12-07
Filing date: 2010-12-07
Publication date: 2012-07-11

Abstract

The invention relates to a preparation method for NaV2O5. According to the invention, sodium carbonate (Na2CO3), vanadium trioxide (V2O3) and vanadium pentoxide (V2O5) are used as raw materials and are mixed according to a mole ratio of 2: 1: 3, and an obtained mixture is sintered in an inert gas atmosphere like a high purity nitrogen atmosphere or an argon atmosphere at a temperature of 600 to 800 DEG C for 10 h so as to obtain NaV2O5 polycrystalline powder. According to the invention, nontoxic Na2CO3 is used to substitute a raw material with great toxicity, NaVO3, used in traditional preparation methods, which enables hazards of an experiment to be reduced and sintering time to be greatly shortened, so the method has great significance to future industrial production and incomparable advantages compared to traditional methods.

Description

A kind of NaV 2O 5The preparation method

Technical field

The present invention relates to a kind of NaV ₂O ₅The preparation method.

Background technology

The Pei Ersi phase transformation is a kind of structural phase transition, in many accurate one dimension systems, can observe.Because magnetic-elasticity phase transformation that the spin dimerization causes is exactly spin-Pei Ersi phase transformation, it is an important theoretical foundation of following spintronics device.Spin-Pei Ersi phase transformation is at organism TTF-CuBDT and MEM (TCNQ) at first ₂Middle discovery.1993, Hase was first at inorganic materials CuGeO ₃Susceptibility experiment in observed spin-Pei Ersi phase transformation.

1996, people such as Japanese scientist Isobe were to NaV ₂O ₅The measurement of susceptibility in find, at T _C<t<during the 300K TR, NaV ₂O ₅It is antiferromagnetic isolator; T ≈ T _C, promptly near the 34K (the highest up to now critical temperature), its susceptibility sharply reduces; T<t _C, system is that insulating does not have magnetic spin singlet state ground state.This phase transformation is called as spin-Pei Ersi phase.To there being a limited band gap the first excited state, so can use the quantum switch that this characteristic is made the control electron spinning, this is having great importance aspect spintronics device application in the future and is being worth from spin singlet state ground state.And the further investigation of spin-Pei Ersi phase transformation has and significant meaning for in-depth and the basic theories of expanding Condensed Matter Physics.

NaV ₂O ₅Be orthohormbic structure during room temperature, have the V of " it " font in its structure ⁴⁺The ion chain, the subcritical temperature, its structure becomes monocline.NaV ₂O ₅In observed spin-Pei Ersi phase transformation and traditional organism and CuGeO ₃Also have some very big difference Deng observed spin-Pei Ersi phase transformation in the material, so traditionally NaV ₂O ₅In observed phase transformation type of being called spin-Pei Ersi phase transformation.So to NaV ₂O ₅Further investigation special theory significance is arranged again.

Because NaV ₂O ₅The V that exists in the structure ⁴⁺Ion chemistry character is unstable, very easily is oxidized to the high V of chemicalstability ⁵⁺Ion perhaps is reduced into the general V of chemicalstability ³⁺So ion is NaV ₂O ₅The preparation difficulty very big, the preparation method only has two kinds of solid state sintering and hydrothermal methods at present.The productive rate of hydrothermal method is low, and is repeatable relatively poor.Conventional solid sintering technology is to adopt NaVO ₃, V ₂O ₃And V ₂O ₅Raw material is according to certain proportioning uniform mixing, and high temperature sintering several days under vacuum or inert gas atmosphere just can obtain NaV then ₂O ₅NaVO in the raw material ₃Human body there is bigger toxicity, so experimentation has certain danger.And whole sintering process for up to several days, these all are unfavorable for suitability for industrialized production in the future.

Summary of the invention

The objective of the invention is to provide a kind of nontoxic yellow soda ash (Na that adopts ₂CO ₃) the bigger NaVO of replacement traditional preparation method toxic ₃Raw material is with yellow soda ash (Na ₂CO ₃), vanadous oxide (V ₂O ₃) and Vanadium Pentoxide in FLAKES (V ₂O ₅) be raw material, according to certain stoicheiometry, utilize solid state sintering in short sintering time, to prepare NaV ₂O ₅The method of polycrystal powder.

Technical solution of the present invention is:

In the methods of the invention solid sintering technology is explored, mainly studied the related chemical reaction process of whole solid-phase sintering process, having searched out to substitute has bigger toxicity NaVO to human body ₃The material of raw material, promptly nontoxic yellow soda ash (Na ₂CO ₃) material.According to Na ₂CO ₃With V ₂O ₅Reaction can generate NaVO ₃Chemical reaction: Na ₂CO ₃+ V ₂O ₅→ 2NaVO3+ CO ₂↑ (I), and preparation NaV ₂O ₅Chemical reaction:

4NaVO ₃+V ₂O ₃+V ₂O ₅→4NaV ₂O ₅（Ⅱ）

Design is carried out these two chemical reactions simultaneously, just can avoid the experimenter to touch deleterious NaVO ₃Material, ideal chemical reaction are chemical reaction (I) both sides to be multiply by two again and chemical reaction (II) addition, the NaVO on the both sides that disappear ₃, promptly

2Na ₂CO ₃+V ₂O ₃+2V ₂O ₅→4NaV ₂O ₅+?2CO ₂↑

Because NaVO ₃Fusing point lower (630 ℃), so (promptly the sintering temperature by chemical reaction (II) can not be higher than 650 ℃ to the normal sintering process, causes the very big prolongation of sintering time.When NaVO ₃Raw material replaces with Na ₂CO ₃After, because Na ₂CO ₃Fusing point high, so the temperature of sintering reaction can be carried out at 700-800 ℃, this will shorten the time of solid state sintering greatly.These improvement can bring great convenience for this material suitability for industrialized production from now on.

Concrete preparation method is: with yellow soda ash (Na ₂CO ₃), vanadous oxide (V ₂O ₃) and Vanadium Pentoxide in FLAKES (V ₂O ₅) be raw material, after the molar ratio mixing according to 2:1:3,600 ℃ of-800 ℃ of sintering can obtain NaV in 10 hours in high pure nitrogen atmosphere ₂O ₅The polycrystal powder sample.

Technical characterstic of the present invention: with nontoxic yellow soda ash (Na ₂CO ₃) the bigger NaVO of replacement traditional preparation method toxic ₃Raw material had both reduced the danger of testing, the short sintering time that greatly contracted again, and these are huge for suitability for industrialized production meanings in the future.So the method that we adopted has the incomparable advantage of traditional method.

Description of drawings

Fig. 1 is that the present invention prepares NaV ₂ O ₅The apparatus sketch that material adopted.

Fig. 2 is the NaV for preparing ₂O ₅The X-ray diffraction spectrogram.

Embodiment

Concrete step of preparation process is following:

Preparation NaV ₂O ₅

1., difference weighing yellow soda ash (Na ₂CO ₃) 2.12 the gram, vanadous oxide (V ₂O ₃) 1.50 grams and Vanadium Pentoxide in FLAKES (V ₂O ₅) 5.45 grams (material purity is more than 99%), with three kinds of raw materials mix, mixture is put into agate mortar then, add 10-15 milliliter absolute ethyl alcohol, grinding mixture all evaporates until absolute ethyl alcohol, so that mixture can mix.

2., mixture is placed ceramic Noah's ark; The pottery Noah's ark is put into quartz apparatus, and quartz apparatus is put into tube type resistance furnace, and quartz apparatus is a tubulose; Connect nitrogen or argon gas gas cylinder with one; The other end connects emulsion tube, and the beaker (experimental installation is seen Fig. 1) that fills certain water gaging is put in the emulsion tube air outlet, opens gas cylinder valve; In quartz apparatus, feed chemically inert gases (purity 99.9%) such as nitrogen or argon gas, ventilation half a hour to one hour (flow velocity 200 ml/min) makes the thoroughly emptying of oxygen quilt in the silica tube under the room temperature.Be warming up to 700 ℃ of sintering then 10 hours, and can obtain NaV after being cooled to room temperature ₂O ₅Polycrystal powder.

The NaV for preparing ₂O ₅X-ray diffraction spectrogram (see figure 2) show that the prepared polycrystal powder that obtains is single NaV ₂O ₅Material is not because find the diffraction peak of other impurity on the X-ray diffraction spectrogram.

Claims

1. NaV ₂O ₅The preparation method, it is characterized in that: this preparation method is with yellow soda ash (Na ₂CO ₃), vanadous oxide (V ₂O ₃) and Vanadium Pentoxide in FLAKES (V ₂O ₅) be raw material, after the molar ratio mixing according to 2:1:3,600 ℃ of-800 ℃ of sintering can obtain NaV in 10 hours under inert gas atmospheres such as high pure nitrogen atmosphere or argon gas atmosphere ₂O ₅Polycrystal powder.

2. a kind of NaV according to claim 1 ₂O ₅The preparation method, it is characterized in that: the described NaV of making ₂O ₅The reaction equation of polycrystal powder: 2Na ₂CO ₃+ V ₂O ₃+ 2V ₂O ₅→ 4NaV ₂O ₅+ 2CO ₂↑.

3. a kind of NaV according to claim 1 ₂O ₅The preparation method, it is characterized in that: described preparing method's concrete steps are:

1., the molar ratio according to 2:1:3 takes by weighing raw material yellow soda ash (Na ₂CO ₃), vanadous oxide (V ₂O ₃) and Vanadium Pentoxide in FLAKES (V ₂O ₅), above-mentioned raw materials is mixed, mixture is put into agate mortar, adds a small amount of absolute ethyl alcohol, and grinding mixture all evaporates until absolute ethyl alcohol, so that mixture can mix;

2., mixture that step is obtained in 1. places ceramic Noah's ark, ceramic Noah's ark is put into quartz apparatus, quartz apparatus is put into tube type resistance furnace; Quartz apparatus is a tubulose, connects nitrogen or argon gas gas cylinder with one, and the other end connects emulsion tube; The beaker that fills certain water gaging is put in the emulsion tube air outlet, opens gas cylinder valve, in quartz apparatus, feeds chemically inert gases such as nitrogen or argon gas; Ventilated under the room temperature 0.5～1 hour, flow 200 ml/min make the thoroughly emptying of oxygen quilt in the quartz apparatus; Be warming up to 700 ℃ of sintering then 10 hours, and can obtain NaV after being cooled to room temperature ₂O ₅Polycrystal powder.