METHOD OF PRODUCING POWDER OF PHASES OF LAYERED TITANATES OF S- AND P-ELEMENTS Russian patent published in 2013 - IPC C04B35/475 C04B35/462 B82B3/00 

FIELD: chemistry.

SUBSTANCE: invention relates to methods of producing powder of phases of layered titanates of s- and p-elements, which are a base for piezoelectric materials that are widely used in modern aerospace industry. The disclosed method of producing phases of layered titanates of the type Bi₂A_n-1B_nO_3n+3 (A= Na, Ca, Cr, Bi) and (B=Ti) consists of three steps: a) synthesis, during acid hydrolysis of sodium titanates, of starting nano-clusters of polymer hydroxides of titanium (IV) at temperatures less than or equal to 370 K, peptisation of the hydrolysis product in a 60% nitric acid solution, and precipitating the nano-clusters from 0.1-0.3M (with respect to TiO₂) colloidal solutions at pH=8±0.5 using 5-10% ammonia solution at temperature below 280°K, b) reaction of the nano-clusters at temperature below 280°K with saturated Bi(NO₃)₃ solution while stirring, c) reaction of the primary intermediate product with a suspension of bismuth (III) hydroxide at standard conditions and thermal decomposition of the intermediate phase at temperature of 600-700°K; isothermal processing time ranges from 20 to 30 minutes. In order to dope with Cr³⁺ ions, a calculated amount of chromium acetate is added to the colloidal solution of titanium (IV) hydroxides at step a); in order to dope bismuth titanate with Na¹⁺ Ca²⁺ ions, sodium and calcium hydroxides are added to the suspension of bismuth nitrate.

EFFECT: low synthesis temperature of titanate phases and improved piezoelectric parameters of materials based thereon.

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