Multiferroic thin-film material of layered perovskite structure and preparation method thereof

Abstract

The invention discloses a multiferroic thin-film material of a layered perovskite structure and a preparation method thereof. The prepared multiferroic thin-film material is characterized in that bismuth, iron, cobalt, titanium and oxygen elements form a thin film, wherein a chemical formula of the thin film is Bin+1Fen-3-xCoxTi3O3n+3, Bi is bismuth, Fe is iron, Co is cobalt, Ti is titanium, O is oxygen, n is more than or equal to 4, n is an integer, and x is more than 0 and less than or equal to (n-3) / 2; meanwhile, thickness of the multferroic thin-film material is 400-1000nm, the multiferroic thin-film material is composed of platy particles arranged compactly, and the particle sizes of the platy particles are 20-300nm. The multiferroic thin-film material has excellent ferroelectric and ferromagnetic properties, a production process is simple and easy to learn, less equipment is required, a sintering magnetic field is low, a sintering phase formation temperature is low, and the preparation cost is low, so that the multiferroic thin-film material is beneficial to large-scale industrial production.

Description

technical field [0001] The invention relates to the technical field of multiferroic materials, in particular to a layered perovskite structure multiferroic thin film material and a preparation method. Background technique [0002] Multiferroic materials are materials that integrate magnetism and electricity, and have magnetoelectric coupling effects. Therefore, multiferroic materials have broad application prospects in spintronics and other fields. However, the types of single-phase multiferroic materials found so far are very limited, and their performance is poor, either the magnetic transition temperature or ferroelectric transition temperature is very low, or the ferroelectric and ferromagnetic properties are very weak, or the magnetoelectric coupling effect is very weak, which is a huge bottleneck for its application. [0003] The preparation methods of multiferroic materials with Aurivillius phase structure in the prior art all have shortcomings. The traditional solid...

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Problems solved by technology

However, the types of single-phase multiferroic materials found so far are very limited, and their performance is poor, either the magnetic transition temperature or ferroelectric transition temperature is very low, or the ferroelectric and ferromagnetic properties are very weak, or the magnetoelectric coupling effect is very weak, which is a huge bottleneck for its application

[0003] The preparation methods of multiferroic materials with Aurivillius phase structure in the prior art all have shortcomings. The traditional solid-state reaction method will lead to uneven dispersion of raw materials, so the composition of the final prepared sample may not be accurate enough, and the powder sintering The temperature for phase formation is usually very high, which will easily lead to the volatilization of bismuth element and the detachment of oxygen from the lattice, thus introducing more bismuth defects and oxygen vacancies. These defects in the preparation method restrict the improvement of the performance of the material.

Although ferromagnetism and ferroelectricity coexist at room temperature in this type of multiferroic material, the remanent electric polarization and remanent magnetization are very small, and there is an obvious leakage current behavior, all of which restrict its application.

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