Magnetic Properties of Some Tellurite Glasses

The AC magnetic susceptibility in the range 5–130 K of the tellurite glass systems: TeO2–MnO2–ZnO–PbO and TeO2–MnO2–V2O5–Fe2O3 was measured and analyzed. The investigations of the AC magnetic susceptibility facilitated the determination of the molar susceptibility, paramagnetic magnetic susceptibility, paramagnetic Curie temperature, and magnetic entropy changes of the tellurite glasses. The results clarified that the temperature dependence of the magnetic susceptibility deviated from the Curie law and the increase of the small negative values of Curie temperature indicated negative interchange interactions between the antiferromagnetically coupled manganese ions within the present glass network. The magnetic moments evaluated from susceptibility measurements of the glasses show the predominance of the Mn2+ valence state than Mn3+ valence state of MnO2.