Anomalous magnetic properties of heavily Tb-doped glasses

Tb-doped glasses usually show a paramagnetic character. Recently, glasses have been successfully doped with Tb3+ ions in heavy concentrations of more than 10 at. %. These glasses show magnetic properties different from the conventional paramagnetic behavior. However the mechanism of their anomalous magnetic properties has not been clarified yet. In this study, we prepared heavily Tb-doped glasses and investigated their magnetic and magneto-optical properties. We observed some results that indicate a slower relaxation process of more than 1.0 sec.