Growth, characterizations, and thermal analysis of rhenium chalcogenides ReS2−xSex (x = 0, 1, and 2) single crystals

The rhenium chalcogenides ReS 2− x Se x ( x = 0, 1, and 2) single crystals are grown at low temperature from the melting point by chemical vapor transport technique. The powder X-ray diffraction analysis of the single-crystals symmetry showed orientation at (001) plane of ReS 2− x Se x ( x = 0, 1, and 2). The energy-dispersive analysis of X-rays showed the crystals to be pure. The optical bandgap obtained of the as-grown single crystals falls in visible range of 1.27 eV to 1.37 eV. The Raman peaks are well assigned to both in-plane and out-of-plane vibrations in the ReS 2− x Se x ( x = 0, 1, and 2). The thermal gravimetric analysis showed that given as-grown single crystals are stable up to nearly 650 K and the differential thermal gravimetric analysis showed that single crystals disintegrate in two steps between ambient and 1233 K temperature range. The differential thermal analysis showed the ReS 2− x Se x ( x = 0, 1, and 2) possesses initial endothermic followed by exothermic nature for fast heating rates. The kinetic parameters determined by the Kissinger relation show that all the single-crystal samples behavior is nearly the same when disintegrate at a higher-temperature range.