Raman spectra and electronic properties of HgTeS crystals at high pressure

The results of transverse magnetoresistance (MR) and Raman spectrum (RS) me asurements (in the region 80-160 cm(-1)) of Hg1-lambdaTexS crystals (0.04 l ess than or equal to x less than or equal to 0.6) at room temperature and h igh pressure P up to 1.5 GPa are presented. The galvanomagnetic measurement s show the change of electronic structure and charge carrier concentration as the sulphur content is rising. The increasing of MR under P and, hence, the increase of electron mobility agree with the certain model of electroni c structure of gapless semiconductors. Three HgTe-like phonon Raman modes w ere observed near about 90, 120 and 140 cm(-1), and one mode near 100 cm(-1 ), which was shifted to lower frequencies in the sulphur-rich samples in ac cordance with theoretical predictions. At P = 1.6 GPa, above the onset of p ressure-induced phase, two alpha -HgS like peaks near 90 cm(-1) were observ ed.