Electrical properties of vanadium phosphate glasses containing antimony and arsenide oxide

Both DC and AC resistivity of some vanadium phosphate glasses containing antimony or arsenic oxide have been measured over a wide temperature range. These glasses contain a finite concentration of Sb<SUP>3+</SUP> and possibly As<SUP>3+</SUP> ions. The data indicate that below 200K conduction takes place via carriers excited to localised states at the band edge which is separated from the Fermi level by approximately 0.08 eV in glasses containing antimony oxide and approximately 0.04 eV in samples containing arsenic oxide. The origin of these states is ascribed to some bond formation between As<SUP>3+</SUP> or Sb<SUP>3+</SUP> and the V<SUP>4+</SUP> ions