The Sn-119-Mossbauer spectra of xSnO.(70-x)SnF2.3OP(2)O(5) glasses (0
less than or equal to x less than or equal to 70) measured at 78 K com
prised a doublet due to Sn2+ (delta = 3.30-3.36 mm s(-1), Delta = 1.70
-1.72 mm s(-1)) and a weak singlet due to Sn4+ located at -0.23 mm s(-
1) with respect to BaSnO3. The delta and Delta of Sn2+ were comparable
to those of Sn2P2O7. Small Debye temperatures (146 and 155 K) were ob
tained from the low-temperature measurements. These results indicate t
hat Sn2+ and Sn4+ occupied interstitial sites, being loosely and ionic
ally bonded to distorted PO4-xFx tetrahedra.