A new thermo-optical method based on the sensitive detection of thermal gradients adjacent to heated sample surfaces is described. Room- and low-temperature experiments were performed using this technique, and its advantages over different methods are discussed.

No abstract

No abstract

No abstract

No abstract

No abstract

No abstract

This paper deals with three problems of ;t different nature. We first discus the conditions required to obtain reliable and usable magneto-optical and absorption data at any temperature down to that of liquid helium; this discussion includes the description of our cryostat and absorption device, as well as a critical study of the optimization of the signal-to-noise ratio of the instruments. Secondly, a new fitting procedure is proposed for the analysis of absorption and magnetic circular dichroism curves and the extraction of useful parameters. Finally, the significance of these parameters is examined for anisotropic centres isolated in an isotropic matrix ; the results thus obtained are illustrated by means of magneto-optical experiments on CaF2 +Nd3+ crystals. * Equip de recherche no. 5 du C.N.R.S. * D is used here for absorbance (A) since this last parameter (A) is widely used in the description of MCD data.