PROCESS FOR PREPARING AI 1-X FE X PO 4 -TYPE SINGLE CRYSTALS WITH Α -QUARTZ STRUCTURE

摘要

The invention relates to a process for preparing piezoelectric single crystal materials of the AIFePO-type with α -quartz structure by hydrothermal technology while using low temperatures and pressures, in acid medium, where the substitution of the Al atom by the Fe atom in the α -quartz-type structure improves the piezoelectric properties, thereby solving the applicative limitations and low performance of quartz. The process claimed by the invention consists in preparing piezoelectric single crystals of the AIFePO-type, where x= 20%, with aplha -quartz structure, under hydrothermal conditions, at pressures ranging between 10...100 bar and temperatures of 150...250°C, in sulphuric acid and phosphoric acid medium, at a molarity ranging between 1...6 M.