Charge transfer in liquid semiconductors: The K-Te system

The neutron diffraction patterns of molten Kₓ{Te}_{1{{-}}x}$ alloys for x=0.12 and x-0.50 demonstrate the persistence of covalently bonded tellurium in the liquid. In the case of liquid ${K}0.12Te0.88, the measured structure is domianted by the Te-Te contribution, and is remarkably similar to that of pure liquid tellurium. The equiatomic alloy K0.50{Te}0.50$ is shown to contain mostly Te pairs which are identified with Zintl ions, ${Te}₂^{2{{-}}}$. The presence of these ions explains the semiconducting behavior of these alloys deduced from recent electrical transport measurements.