COMPOSITE PIEZOMATERIAL AND METHOD FOR ITS MANUFACTURE Russian patent published in 2021 - IPC C04B35/491 C04B35/497 C04B35/472 C04B35/634 H01L41/83 

FIELD: piezoelectric materials.

SUBSTANCE: invention relates to composite piezoelectric materials (CPM) and can be used for the manufacture of hydroacoustic receivers, sensors for medical ultrasound diagnostics, emission control, flaw detectors and other volume-sensitive piezoelectric converters, as well as for the manufacturing technologies of these materials. The composite piezoelectric material includes ceramic ferroelectric films made of ultrafine powders of ferroelectric phases of the oxygen-octahedral type: lead zirconate/titanate, or lead methaniobate, or lead titanate, or solid solutions based on them, located parallel to each other and connected by at least two acrylic-based polymer films, which are located opposite to each other in the plane of the ceramic films in the direction of the polarization vector of the composite material and whose dimensions ensure the formation of an air cavity between them. Electrodes connected by current leads are applied to the end surfaces of ceramic films. The ceramic film is obtained from a slip of the composition, weight percentage: ultrafine powder of ferroelectric phases 63.05-74.60, distilled water 12.40-18.55, binder (aqueous dispersion of ethyl-(methyl-)acrylates and dibasic unsaturated carboxylic acid copolymers) 8.05-12.00, plasticizer 1.10-4.20, dispersant (7-12%, an aqueous solution of vinyl acetate and maleic acid copolymer, in which 0.8-1.5 equivalents of carboxylic acids groups neutralized with ammonia) 0.36-0.95, as well as non-ionic surfactants 1 and 2, thickener, defoamer. The method for manufacturing CPM includes the assembly of CPM from separate sintered ceramic films with electrodes with current leads applied to the end surfaces, connected to acrylic polymer films separated by an air cavity, and the formation of two electrodes with current leads connecting separately the upper electrodes of ceramic films and the lower electrodes of ceramic films.

EFFECT: increase in the values of the volumetric piezomodule (d_v) and the reception factor (d_v⋅g_v), while maintaining or increasing (in the case of equal volume fractions of the ferroelectric phase in the system) the values of the volumetric piezo sensitivity (g_v) and dielectric permittivity (ε^Т₃₃/ε^о), as well as simplifying the method for its manufacture.

18 cl, 5 dwg, 4 ex, 1 tbl