Bismuth ferrite based nano ceramic and preparation method

Abstract

The invention discloses bismuth ferrite based nano ceramic. A main composition of the nano ceramic is Bi0.8Gd0.2Fe1-xTixO3, wherein value of x is doping proportion of Ti4+, x is greater than or equalto 0.01 and smaller than or equal to 0.1, and phase of Bi0.8Gd0.2Fe1-xTixO3 is orthogonal phase. Spiral cycle of bismuth ferrite based ceramic is broken through, ferromagnetism and ferroelectricity ofthe bismuth ferrite based nano ceramic are improved, and dielectric loss and leaking current are reduced. The invention further discloses a preparation method of the bismuth ferrite based nano ceramic. The preparation method includes following steps: weighing a bismuth source, an iron source, a gadolinium source and a titanium source, mixing and dissolving in an organic solvent to preparing a mixed solution, adding an additive, and stirring to obtain sol; drying the sol, and finely grinding to obtain nano powder; filling a graphite die with the nano powder, performing plasma sintering, polishing and grinding to remove carbon paper on the surface, and annealing to obtain the bismuth ferrite based nano ceramic. By adopting plasma sintering, compactness of the bismuth ferrite based nano ceramic is improved, so that ferromagnetism is enhanced, and generation of the orthogonal phase in the bismuth ferrite based nano ceramic is promoted.

Description

technical field [0001] The invention relates to the technical field of preparation of electrodeless non-metallic materials, in particular to a bismuth ferrite-based nano-ceramic and a preparation method thereof. Background technique [0002] Bismuth ferrite (BiFeO 3 , BFO), is a twisted triangular perovskite structure, with high Curie temperature, Neel temperature and large remnant polarization temperature, in ferroelectric random access memory, spintronic devices, magnetoelectric memory units , optoelectronic devices and other fields have good application prospects. [0003] In bismuth ferrite, the Bi element is volatile at high temperature, and it is difficult to form a pure phase, and the Fe element is easily changed to produce Fe 2+ , resulting in electrons in the Fe 2+ / Fe 3+ The jump between them makes the dielectric loss of the system too large, and its own structure has an asymmetric helical structure with a period of 62nm, so the system reflects antiferromagneti...

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Problems solved by technology

[0004] Although the prior art improves the ferromagnetism of bismuth ferrite ceramics, when the doping does not change its antiferromagnetic structure, the leakage current is large. At the same time, due to the doping elements in the prior art, its ferroelectricity is deteriorated. The remanent polarization of bismuth ferrite ceramics is significantly reduced, and the remanent polarization is only 1 μC / cm under some conditions 2

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