High pressure-induced state of variable valence in samarium monochalcogenides

A study was made on peculiarities of electric transfer processes and on parameters of isomorphous phase transition of semiconductor-metal in SmX (X=S, Se, Te). For this purpose basic dependences of specific electric resistance ρ and thermo-emf of this compounds under hydrostatic compression of 8 GPa maximum and quasihydrostatic one of 12 GPa maximum were investigated. Dependences of activation energy on pressure in 300-450 K range, obtained according to ρ isobars are presented. It was established that transfer along the energy f-band affected sufficiently the transport effects in SmX semiconductor phases. Stable of intermediate valency in SmX exists in wide baric range. 7 refs.; 3 figs