Spin glass in semiconducting KFe$_{1.05}$Ag$_{0.88}$Te$_{2}$ single crystals

Abstract

We report discovery of KFe$_{1.05}$Ag$_{0.88}$Te$_{2}$ single crystals with semiconducting spin glass ground state. Composition and structure analysis suggest nearly stoichiometric I4/mmm space group but allow for the existence of vacancies, absent in long range semiconducting antiferromagnet KFe$_{0.85}$Ag$_{1.15}$Te$_{2}$. The subtle change in stoichometry in Fe/Ag sublattice changes magnetic ground state but not conductivity, giving further insight into the semiconducting gap mechanism.