Effects of transition metal additives on GeS glasses

By the addition of Mn or Ni into Ge₄₂S₅₈, a large electrical conductivity increase has been observed in the thermally evaporated sample in contrast with the melt-quenched sample. Mn is supposed to be substitutionally incorporated into amorphous network in negative charge state, working as an acceptor. In the case of Ni, the predominance of variable range hopping type conduction obscures the incorporation scheme of Ni. From ESR measurements, the incorporation scheme of Mn and Ni is found to be different between the evaporated sample and the melt-quenched sample.