A lead-free multiferroic material with relaxor ferroelectric properties and its preparation method

Abstract

The invention discloses a lead-free multiferroic material with relaxor ferroelectric properties and a preparation method thereof. The chemical formula is Ca 3 CoMn 1‑ x Cr x o 6 , where 0.05≤ x ≤0.15, the crystal is orthorhombic structure, space group R‑3c. The weighed CaCO 3 、C 4 h 6 CoO 4 4H 2 O, C 4 h 6 MnO 4 4H 2 O, CrN 3 o 9 Dissolve in citric acid solution, add ethylene glycol to enhance the solution viscosity, then adjust the pH of the mixed solution to 3‑5, put it into a water bath and heat it to make the solution a jelly-like wet gel; dry the wet gel to obtain dry gel; and then through grinding, pre-sintering, secondary grinding, tableting, and sintering to obtain the lead-free multiferroic material. The particle size of the sample is uniform, and it not only has multiferroic characteristics, but also has obvious relaxation characteristics in its ferroelectric phase transition, and its electric dipole moment can be regulated by a magnetic field to promote its application in multifunctional devices.

Description

technical field [0001] The invention relates to the field of relaxor ferroelectric materials and multiferroic materials, in particular to a lead-free multiferroic material Ca with relaxor ferroelectric properties 3 CoMn 1-x Cr x o 6 (0.05≤ x ≤0.15) and preparation method. Background technique [0002] Multiferroic materials refer to materials with two or more iron orders at the same time. This kind of materials can have both spontaneous polarization order and spin order at a certain temperature, and the magnetoelectric coupling effect caused makes multiferroics Materials have certain special physical properties. The characteristic of ferroelectric materials is that they have spontaneous polarization when no external electric field is applied, and the direction of their spontaneous polarization can be reversed or reoriented by an external electric field. Among the ferroelectrics, there is a class called relaxor ferroelectrics, which have a high dielectric constant and a...

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Problems solved by technology

[0003] However, most of the relaxor ferroelectric materials currently used are lead-based single crystals or ceramics. Because the toxicity of lead will bring great harm to the environment and human health, it is of great significance to find new lead-free relaxor ferroelectric materials.

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