METHOD OF PRODUCING BISMUTH FERRITE FILMS AND APPARATUS FOR ELECTROSTATIC SPRAYING Russian patent published in 2020 - IPC C04B35/26 C23C16/448 

FIELD: manufacturing technology.

SUBSTANCE: invention relates to the technology of making bismuth ferrite films, which is a multiferroic and can be used in microelectronics, spintronics, sensorics, in devices for recording, reading and storing information, in photocatalysis, etc. Method of producing ferrite films of bismuth involves preparation of an initial solution of a mixture of bismuth and iron salts, subsequent spraying of the initial solution onto a substrate and annealing. Initial solution is prepared by diluting aqueous solution of mixture of bismuth nitrate and iron nitrate, taken in ratio of 1:1 at concentration of 98–102 g/l (in terms of BiFeO₃), ethyl alcohol with respect to ethyl alcohol : aqueous solution of a mixture of bismuth and iron nitrates 7–5:1. Spraying of initial solution is carried out by electrostatic spraying on conducting substrate, heated to 350–450 °C, at voltage of 7–10 kV and feed rate caused by initial solution pressure equal to 0.02–0.06 ml/min, with size of working zone of electrostatic field of 3–4 cm for 10–20 minutes with supply to upper part of electrostatic field heated to argon temperature of 60–70 °C at rate of 1–5 ml/min and subsequent annealing at temperature of 700–800 °C for 10–20 s. Installation for electrostatic spraying, used in method, additionally comprises another heater, into which through pipeline equipped with reduction gear and valve, argon is supplied from container, then fed through pipe to electrostatic field top directly to outlet, wherein both heaters are connected to one power supply unit, and outlet hole is equipped with electrostatic field value regulator.

EFFECT: method of obtaining films of bismuth ferrite provides simplification of the process and reduction of its duration.

3 cl, 5 dwg, 3 ex