Thermoelectric and galvanomagnetic properties of Sulphur at ultrahigh pressure

Thermoelectric power of Sulphur have been measured at high pressure P up lo 45 GPa. It was shown, that conductivity of Sulphur above P∼30 GPa is due to holes of valence band like the rest semiconductors of VI Group-Te and Se. From dependence of thermoelectric power on P the decreasing of semiconductor gap E_g down to ∼0.4 eV at ∼40 GPa have been determined. Negative magnetoresistance MR of Sulphur established at P≈30 GPa pointed to low mobility of holes and implied indirect semiconductor gap Transformation of Sulphur electronic structure under pressure is discussed in a terms of the model of Peierls distortion of lattice.