Luminescence method for the study of Nd3+ ions diffusion in AgBr crystals

Abstract

This study of diffusion of Nd in AgBr is motivated by our interest in the preparation of Nd-doped AgBr crystals that show lasing effects in the near and midinfrared. The doping can be done in several ways. We propose that monitoring the infrared luminescence along the direction of diffusion of activator ions in crystals of AgBr is a sensitive and minimally invasive method of determining the diffusion coefficient, the diffusion enthalpy, and the temperature dependence of these parameters for ions of interest. We have used this technique to study the diffusion of Nd3+ in AgBr crystals. To establish the concentration range in which the luminescence method is useful, the dependence of the luminescence kinetics on the Nd-ion concentration was investigated. The temperature dependence of the diffusion coefficient (D0=1.2×10−5 cm2/s at room temperature), and the diffusion enthalpy (H=0.51 eV) were determined. We found that high values of the diffusion coefficient and low values of the diffusion enthalpy facilitate preparation of high optical quality Nd-doped AgBr crystals. Such crystals are candidates for lasing action.