Electron spin resonance of vitreous lithium boromolybdates

The electron spin resonance spectra of B 2 O 3 -Li 2 O-MoO 3 glasses reveal paramagnetic Mo(V) ions in small concentrations, whereas the Mo(VI) ions are diamagnetic. The glasses had either a constant Mo content corresponding to the formula (10-y)B 2 O 3 , yLi 2 O, MoO 3 , with 1≤y≤4.1,or a constant B 2 O 3 /Li 2 O ratio, corresponding to the formula 7B 2 O 3 , 2Li 2 O, zMoO 3 , with 0.25≤z≤2.5