Optical studies in gamma irradiated Mg doped CaF2 single crystals

Abstract

Pure and Mg doped CaF 2 single crystals grown by the Bridgman method were irradiated with gamma rays (γ-rays) for doses ranging from 97 Gy to 9.72 KGy. The pristine samples showed minimal absorption indicating the purity of the samples. The γ-irradiated pure CaF 2 crystals showed prominent and strong absorption with a peak at~374 nm besides three weak ones at~456, 523 and 623 nm. However γ-rayed Mg doped crystals showed a prominent absorption with a strong peak at~370 nm and a broad one at~530 nm. The absorption indicated the generation of F and F-aggregate centers in the irradiated crystals. The photoluminescence (PL) emission spectrum of both pure and Mg doped crystals showed prominent emission at~390 nm when they were excited at~250 nm. Also, when the samples were excited at 323 and 363 nm strong emissions were observed at~430 and 422 nm respectively. The optical absorption and PL intensities were found to increase with increase in dose.

Morphology and optical properties of Mg and Sr doped CaF2 nanocrystals

“…However, reports on Mg and Sr doped CaF 2 are very rare. The authors have recently studied optical properties of gamma rayed Mg doped CaF 2 single crystals [7]. In the present work Mg and Sr doped (2 mol% each) CaF 2 nanocrystals are synthesized by co-precipitation method and characterized by X-ray diffraction (XRD), Scanning electron microscopy (SEM), Infra red spectroscopy (FTIR), Optical absorption and Photoluminescence (PL) techniques.…”