Magnetic properties of cerium doped oxide glasses below 1 K

Temperature dependences of the magnetic susceptibilities from 1 K >T > 0.015 K have been determined as functions of cerium concentration for a number of cerium doped borate and silicate glasses. The magnetic susceptibility of all glasses was found to obey a Curie-Weiss Law in the temperature range studied and the Curie and Curie-Weiss constants, λ and θ respectively, were found to scale linearly with cerium composition independent of the glass type. Magnetic ordering temperatures were estimated from magnetic cooling studies. Contrary to the similarity in the glasses above 0.015 K, it was observed that borate glasses order systematically lower in temperature than silicate glasses for given cerium concentrations.