Phosphorescence of s-triazine vapor
Abstract The phosphorescence of s -triazine vapor has been observed by means of time-resolved emission spectroscopy. The phosphorescence spectrum is diffuse with a faint vibronic structure in the shorter-wavelength region. The phosphorescence quantum yield is 3.0 × 10 −5 for excitation at the 6 2 0 absorption band of the S 0 → S 1 transition, and the lifetime is 7.1 × 10 −6 s.
The study of the structural transition in nanoscale materials is of particular interest for their potential applications. In the present study, we have observed a lower temperature T = 250??C for the phase transition from the sphalerite structure to the wurtzite structure in ZnS nanoparticles under a pressure of 1?GPa, as compared to those, T = 400 and 1020??C, for ZnS nanoparticles and bulk ZnS under normal pressure, respectively. The reduced transition temperature is attributed to the applied pressure leading to tight particle?particle contacts, which change the surface (or interfacial) environment of the nanoparticles and thus their surface (or interfacial) energy.