B-site ordered and oxygen-deficient perovskite Sr_(4-x)Ca_xGaTaO_8(x=0,1,2,3,4): syntheses and structural characterizations by powder X-ray diffraction

【摘要】：正The solid solutions Sr4-xCaxGaTaO8(x=0,1,2,3,4) have been synthesized by high temperature solid state reaction in air. The crystal structureswere determined from power X-ray diffraction(XRD), which all crystallize in the monoclinic space group P21/c. Sr4GaTaO8 is isostructural to the previous reported Sr4AlNbO8, whichin fact is a B-site ordered and oxygen-deficient triple perovskite