AMORPHOUS TO CRYSTALLINE TRANSFORMATION OF COLD CONDENSED TLBR FILMS

High quality amorphous films of TlBr which are completely transparent below the absorption edge were obtained by the deposition of the substance onto cold substrates kept at 77 K. The films shows a sharp crystallization behavior upon heating in a small temperature range, less than 1.5 K near 95 K for a film about 1700 angstrom thick. The as-crystallized films just above the crsytallization temperatures have microcrystalline nature characterized by the absence of the first exciton band; the exciton band grows at higher temperatures.