Method for preparing giant field induced strain barium titanate single crystal

Abstract

The invention relates to a method for preparing giant field induced strain barium titanate single crystal. Positions of tetravalent titanium ions in crystal lattices are replaced by using doped trivalent ions, and the positions and oxygen vacancies in the crystal form a defective dipole moment. A barium titanate single crystal sample is prepared according to the length, width and thickness along the [100], [010] and [001] directions respectively; and electrodes are prepared on the surfaces of the sample in the width and thickness directions. A transverse electric field slightly higher than a coercive field is applied to the lateral electrode of the sample, the temperature of the sample is raised to a certain temperature below Curie temperature, and the sample is aged for over 1 day. In the ageing process, the spontaneous polarization direction of a domain in the sample is turned to an ageing electric field direction to form a single domain structure; and meanwhile, the defective dipole moment in the single crystal accelerates the diffusion motion under temperature rise, and under the action of the ageing electric field, the electric polarization direction of the defective dipole moment is gradually kept in accordance with the direction of the ageing electric field.

Description

technical field [0001] The invention relates to a preparation method of giant field-induced strained barium titanate single crystal. Background technique [0002] Common piezoelectric materials produce field-induced strain due to the fretting of ions in an electric field. However, the electric deformation of this general piezoelectric effect is very small, which restricts the practical applicability of this material. Under the electric field of 200V / mm, the strain of general PZT piezoelectric ceramics is less than 0.02%. And due to adverse effects on human health, these lead-containing piezoelectric materials, which are still widely used today, have begun to be subject to more and more restrictions. In this way, more and more attention has been paid to the research on non-lead-containing piezoelectric materials, such as barium titanate single crystal, which can produce huge deformation by using 90-degree domain inversion, and its strain can be higher than that of ordinary p...

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Problems solved by technology

[0003] In order to solve the problem that the huge strain generated by the 90-degree domain flip in the tetragonal phase ferroelectric single crystal is only an irreversible one-time effect, the present invention provides a method for preparing barium titanate ferroelectric single crystal. , it is easy to obtain the reversible giant field strain effect

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