Structural and magnetic ordering in nanoparticles of complex 3d- and 4f-element oxides in germanate glass

Abstract

Germanate glasses doped simultaneously with Fe and rare earth elements Gd, Tb, Dy, and Ho in concentrations of several percent have been investigated. It is shown that the phase state of paramagnetic elements changes from isolated ions and small clusters in the initial glass to crystalline magnetic nanoparticles in the samples subjected to heat treatments. The field dependences of the magnetization of such samples are characterized by magnetic saturation in fields of about 1 kOe and large Faraday rotation in the near-IR region (up to 10 deg/cm in the range from 700 to 800 nm).