Структурные особенности фосфатов Ca-=SUB=-9-x-=/SUB=-M-=SUB=-x-=/SUB=-Dy(PO-=SUB=-4-=/SUB=-)-=SUB=-7-=/SUB=- (M=Zn-=SUP=-2+-=/SUP=-, Mg-=SUP=-2+-=/SUP=-)

Abstract

Solid solutions of phosphate with whitlockite-type Ca9-xMxDy (PO4) 7 (M = Zn2 +, Mg2 +) were obtained. The samples were studied by a complex of methods, such as X-ray phase analysis, second harmonic generation, and luminescent spectroscopy. It was established that in the series of solid solutions a change in the symmetry of the unit cell R3c-> R 3c is observed during Ca2+ -M2+ substitution, and the concentration dependence was determined. The phase transitions of the ferroelectric and antiferroelectric type and their temperature position were established by dielectric spectroscopy. The synthesized samples demonstrate intense luminescence with 350 nm excitation and the resulting radiation is in the white region of color coordinates (CIE).