Electrical conductivity, electrochemical and optical properties of Cu7GeS5I-Cu7GeSe5I superionic solid solutions

  • I.P. Studenyak
  • V.V. Bilanchuk
  • O.P. Kokhan
  • Yu.M. Stasyuk
  • A.F. Orliukas
  • A. Kežionis
  • E. Kazakevičius
  • T. Šalkus


Single crystals of Cu7GeS5I–Cu7GeSe5I superionic solid solutions were grown by chemical transport. Their electrical conductivity in the frequency range 1.0⋅106–1.2⋅109 Hz and in the temperature range 100–300 K was measured; the compositional dependences of the electrical conductivity and activation energy were obtained. Electrochemical studies of Cu7GeS5I–Cu7GeSe5I solid solutions were performed, the character of compositional variation of the electrode potential and the range of the electrochemical stability at S→Se substitution were determined. The optical absorption edge of Cu7GeS5I–Cu7GeSe5I superionic solid solutions in the temperature range 77–300 K were studied; the compositional dependences of the optical pseudogap and Urbach energy were obtained.
Keywords: superionic conductors, electrical conductivity, electrochemical properties, optical absorption edge
PACS: 72.80.Jc, 78.40.Ha
Condensed Matter Physics and Technology