MOSSBAUER AND ELECTRON-SPIN-RESONANCE INVESTIGATION OF THE EFFECT OF HEAT-TREATMENT ON THE STRUCTURAL UNITS AND MAGNETIC-PROPERTIES OF IRON VANADIUM BOROPHOSPHATE GLASSES

In our previous work /1/, the behaviour of iron addition to vanadium borophosphate (V.B.P.) glasses (78 mole% V2O5,15 mole% P2O5, 7 mole% B2O3 and x mole% Fe2O3 where (0.5 less-than-or-equal-to x less-than-or-equal-to 50) was investigated by (ME) and (ESR) techniques. In the present work, the investigations were extended to study the effect of heat treatment (H.T) on the same system (up to x = 7.5 mole% Fe2O3). The results obtained showed that heating these glasses at the glass transition temperature (T(g) = 350-degrees-C) for different periods up to 120 min. highly affected their structural units and magnetic properties. The extent of this effect depends on the iron content as well as on the H.T period.