Photoluminescence spectra of S-2(-) center in natural and heat-treated

摘要

The emission and excitation spectra of yellow luminescence due to S-2(-) in scapolites (#1 from Canada and #2 from an unknown locality) were observed at 300, 80 and 10 K. Emission and excitation bands at 10 K showed vibronic structures with a series of maxima spaced 15-30 and 5-9 nm, respectively. The relative efficiency of yellow luminescence from scapolite #2 was increased up to 117 times by heat treatment at 1,000 degrees C for 2 h in air. The enhancement of yellow luminescence by heat treatment was ascribed to the alteration of SO32- and SO42- to S-2(-) in scapolite.