Magnetism of β′-Gd2(MoO4)3 and photoluminescence of β′-Eu2(MoO4)3 crystallized in rare-earth molybdenum borate glasses

Ferroelastic beta'-Gd-2(MoO4)(3) and beta'-Eu-2(MoO4)(3) crystals were synthesized through the crystallization of 21.25Gd(2)O(3)-63.75MoO(3)-15B(2)O(3) glass and 22.5Eu(2)O(3)-47.5MoO(3)-30B(2)O(3) glass, respectivelty, and their magnetism and photoluminescence properties were examined. It was demonstrated from the temperature dependence of the magnetic susceptibility and specific heat down to T = 1.8 K that the magnetic state of Gd3+ ions in the crystallized samples, i.e., in the beta'-Gd-2(MoO4)(3) crystals and the residual glasses, is paramagnetic and any magnetic interaction is not formed among Gd3+ ions down to T = 1.8 K, i.e., the effective magnetic moment of mu(eff) = 7.94 mu(B) and Weiss constant of theta = -0.3 K. Photoluminescence (PL) of Eu3+ ions was clearly observed in the crystallized samples, although the melt-quenched glass did not show any photoluminescence. The present study proposes that the concentration quenching among Eu3+ ions in beta'-Eu-2(MoO4)(3) crystals is small and beta-RE2(MoO4)(3) crystals would be good hosts for PL emissions of RE3+. (C)2013 The Ceramic Society of Japan. All rights reserved.