EPR, IR AND MAGNETIC-SUSCEPTIBILITY STUDIES OF XCR2O3(1-X)[2B2O3.LI2O] GLASSES

The chromium-ions valence states and their distribution mode in xCr2O3 (1 - x)[2B2O3 . Li2O] glasses with 0.5 less-than-or-equal-to x less-th an-or-equal-to 20 mol% are investigated by EPR, IR and magnetic suscep tibility measurements. EPR spectra indicate the presence of both Cr3and Cr5+ ions. These results correlated with magnetic susceptibility d ata show that for x greater-than-or-equal-to 3 mol % the isolated Cr3 ions coexist with those coupled by dipole-dipole or superexchange int eractions. IR spectra confirm the amorphous nature of the studied samp les.