Vibrational study of HgGa2S4 under high pressure
Journal of Applied Physics
Stimulated crystallization of melt-quenched Ge2Sb2Te5 films employing femtosecond laser double pulses J. Appl. Phys. 112, 123520 (2012) Controlled joining of Ag nanoparticles with femtosecond laser radiation J. Appl. Phys. 112, 123519 (2012) Structural, elastic, and vibrational properties of layered titanium dichalcogenides: A van der Waals density functional study In this work, we report on high-pressure Raman scattering measurements in mercury digallium sulfide (HgGa 2 S 4 ) with defect
... ) with defect chalcopyrite structure that have been complemented with lattice dynamics ab initio calculations. Our measurements evidence that this semiconductor exhibits a pressure-induced phase transition from the completely ordered defect chalcopyrite structure to a partially disordered defect stannite structure above 18 GPa which is prior to the transition to the completely disordered rocksalt phase above 23 GPa. Furthermore, a completely disordered zincblende phase is observed below 5 GPa after decreasing pressure from 25 GPa. The disordered zincblende phase undergoes a reversible pressure-induced phase transition to the disordered rocksalt phase above 18 GPa. The sequence of phase transitions here reported for HgGa 2 S 4 evidence the existence of an intermediate phase with partial cation-vacancy disorder between the ordered defect chalcopyrite and the disordered rocksalt phases and the irreversibility of the pressure-induced orderdisorder processes occurring in ordered-vacancy compounds. The pressure dependence of the Raman modes of all phases, except the Raman-inactive disordered rocksalt phase, have been measured and discussed.