STUDY OF POSITRON ANNIHILATION ONE DIMENSION ANGULAR-CORRELATION RADIATION ON POLYCRYSTAL Na^+ CONDUCTOR Na_5Y_(1-x)Cr_xSi_4O_(12)

摘要

With positron annihilation radiation onedimension angular-correlation device,it ismeasured that positron annihilation radiationone dimension angular-correlation curves ofpolycrystal sodium ion conductor Na5Y1-xCrxSi4O12（NYCS）system.After electronmomentum distribution curves arenormalized,linear parameters arecalculated.The parameters H,W and Sshow the change of Na+ ion vacancyconcentration in NYCS series samples.Theresults show that parameters H,W and S ofone dimension angular-correlation curves ofthose samples vary greatly with Cr2O3contents.With Cr2O3 content increasing,Hand S parameters increase,but W decreases,and reaches extremes at x=0.05;then withCr203 adding continually,parameters H andS decrease gradually,parameter W increasesgradually.This shows that,in addtion toCr2O3,the conductivity has close