Rare-earth NMR spectroscopy: a new approach towards the structural characterization of crystalline, ceramic and glassy laser materials - de Camargo, Andrea Simone Stucchi; Nunes, Luiz Antônio de Oliveira; Mohr, Daniel; Araújo, Carla Calvaca de; Eckert, Hellmut; Botero, Ériton Rodrigo; Garcia, Ducinei; Eiras, José Antonio (Encontro Nacional de Física da Matéria Condensada - ENFMC, 2007)