IDENTIFICATION OF TRACE IMPURITIES IN PURE AND DOPED YALO3 AND Y3AL5O12 CRYSTALS BY THEIR FLUORESCENCE AND BY THE EMA METHOD

Trace uncontrolled impurities as Ce3+, Cr3+, Eu3+ and Nd3+ were detect ed in YAlO3 and YAlO3 : Cr crystals from their fluorescence by high se nsitive photon counting detection. The concentrations of Ce, Cr, Eu, N d and some other impurities (Tm, Ho, Mn, Mg, Fe) were also determined by electron beam excited X-ray microanalysis (abbr. EMA) in YAlO3 and Y3Al5O12 crystals (pure or doped). Both the methods (fluorescence dete ction and EMA) are compared, fluorescence properties of some trace imp urities were determined and their influence on local distribution and transfer processes (Ce3+ --> Nd3+, Cr3+ --> Nd3+) in these crystals ar e discussed.