A Debye temperature (OD) of 378 (+5 K) has been obtained by applying a simplified Debye model to the 57Fe M6ssbauer spectra of 60CaO.39Ga203.57Fe203 glass. The 0 D value is comparable to those (280 580 K) obtained so far in several oxide glasses, glass-ceramics, and ceramics in which M6ssbauer atoms are covalently bonded to oxygen atoms and play a role of network former. It proves that Fe(III) atoms occupy the substitutional sites of Ga(III) constituting distorted GaO 4 tetrahedra.