Preparation method of perovskite-structure relaxor ferroelectric single crystal lead indium niobate-lead magnesium niobate-lead titanate

Abstract

The invention relates to a preparation method of perovskite-structure relaxor ferroelectric single crystal lead indium niobate-lead magnesium niobate-lead titanate. The chemical composition of the perovskite-structure relaxor ferroelectric single crystal lead indium niobate-lead magnesium niobate-lead titanate is (1-x-y)Pb(In1 / 2Nb1 / 2)O3-yPb(Mg1 / 3Nb2 / 3)O3-xPbTiO3, wherein x is equal to 0.20-0.45 and y is equal to 0.15-0.70. The preparation method comprises the following steps: (1) preparing a primary crystal growth raw material; (2) primarily growing crystals; (3) preparing secondary crystal growth raw material; and (4) secondarily growing the crystals. According to the preparation method disclosed by the invention, a crucible descending multi-growth method is adopted, the component segregation of wafers can be obviously suppressed, the high-performance areas of the crystals can be expanded, and relaxor ferroelectric single crystal material PIMNT with large dimensions, large high-performance intervals and high quality can be grown effectively with regard to the optimally-orientated wafers for different applications, thus the utilization rate of the crystals is increased, and the difficulties of batch growth and applications of single crystals can be overcome.

Description

technical field [0001] The invention relates to a method for preparing a perovskite structure relaxor ferroelectric single crystal material, in particular to a method for preparing lead indium niobate-lead magnesium niobate-lead titanate relaxor by using the crucible descent method (Bridgman method) A method for a ferroelectric single crystal material belongs to the technical field of crystal material growth. Background technique [0002] Relaxor ferroelectric single crystals with a perovskite structure are high-performance functional materials with multiple uses that have been successfully prepared and widely studied in recent years. Take the relaxor ferroelectric single crystal lead magnesium niobate-lead titanate ((1-x) PMN-xPT (abbreviated as PMNT or PMN-PT) that has been used as an example, it is near the quasi-isomorphic phase boundary (x =0.30~0.34) has excellent dielectric, piezoelectric, ferroelectric and pyroelectric properties (dielectric coefficient ε~4500, diel...

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Problems solved by technology

[0006] The present invention aims at the defects and problems of the above-mentioned prior art, and aims to provide a relaxation ferroelectric unit prepared by the improved Bridgman method through multiple growths of lead indium niobate-lead magnesium niobate-lead titanate crystalline materials to solve the serious segregation of PIMNT single crystal components in the prior art, the small area of ​​high-performance wafers, low crystal utilization rate, and high cost, which make it difficult to prepare and apply PIMNT single crystals in large quantities. Controlled growth of large-sized PIMNT crystals provides a class of practically applicable products for the application of relaxor ferroelectric functional materials, meeting the application requirements of medical ultrasound imaging, sonar, non-destructive detection, drivers, and infrared pyroelectric detection.

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