Preparation method of hexagonal-phase dicerium trioxide monocrystal film

Abstract

The invention provides a preparation method of a hexagonal-phase dicerium trioxide monocrystal film, which comprises the following steps: providing a reaction chamber which comprises a sample table; loading the cerium block into an evaporation source; the reaction chamber is vacuumized; heating the evaporation source; the method comprises the following steps: providing a tungsten single crystal substrate, and processing the tungsten single crystal substrate to obtain an atomic level flat surface; the processed tungsten single crystal substrate is placed on the sample table; continuously heating the evaporation source to obtain a cerium film; oxygen is filled into the reaction chamber, so that the cerium film is oxidized into hexagonal-phase dicerium trioxide; and carrying out annealing on the hexagonal-phase dicerium trioxide so as to obtain the hexagonal-phase dicerium trioxide single crystal thin film. The hexagonal-phase dicerium trioxide single crystal film prepared by the method is relatively high in purity.

Description

[0001] This application is a divisional application with an application date of April 21, 2020, an application number of 202010318599.9, and an invention title of "Hexagonal phase cerium oxide single crystal thin film and its preparation method and application". technical field [0002] The invention relates to the technical field of hexagonal phase cerium oxide, in particular to a method for preparing a hexagonal phase cerium oxide single crystal thin film. Background technique [0003] Cerium ions have two different chemical valence states, positive trivalent and positive tetravalent, so the most common stoichiometric cerium oxides are: hexagonal cerium oxide containing only trivalent cerium ions and tetravalent cerium ions only cerium dioxide. Since the chemical valence state of cerium ion is very easy to convert, there are many non-stoichiometric oxidation forms between hexagonal ceria and ceria. Cerium oxide at normal temperature and pressure is relatively stable, but ...

AI Technical Summary

Problems solved by technology

Cerium oxide at normal temperature and pressure is relatively stable, but under high temperature or reducing atmosphere, the tetravalent cerium ions in cerium oxide can be partially reduced to trivalent and transformed into non-stoichiometric cerium oxide or even hexagonal phase Cerium oxide, but generally speaking, it is difficult to be completely transformed into hexagonal phase cerium oxide

And under normal conditions, the hexagonal phase cerium oxide is extremely unstable and is easily oxidized to tetravalent cerium, so it cannot exist and store stably in the atmospheric environment

In the prior art, the research on hexagonal ceria is usually obtained by re-reducing ceria at high temperature, but in most cases, hexagonal ceria is mixed with ceria of other structures, and relatively purer ceria can rarely be obtained. Hexagonal phase cerium oxide, so its intrinsic fundamental properties are less studied

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