Anomalous behaviour of the EPR spectra of defects in (Y,Sm)123 ceramics with oxygen deficiency at low temperatures
Guskos N, Likodimos V, Typek J, Wabia M, Fuks H. Anomalous behaviour of the EPR spectra of defects in (Y,Sm)123 ceramics with oxygen deficiency at low temperatures. Materials Science Forum [Internet]. 1997;239-241:77-80.
The temperature dependence of the EPR spectra of Y0.5Sm0.5 Ba2Cu3O6+x ceramic in tetragonal phase has been investigated at low temperatures. The complicated EPR spectra resulted from different paramagnetic centers: isolated divalent copper ions, exchange coupled copper pairs of ions, and molecular oxygen ions. The observed temperature dependence of the linewidth of exchange coupled copper ions has been interpreted in frames of a model of the collective motion of magnetic moments. The intensity of EPR spectra of molecular oxygen ions has shown critical behaviour at 3.60 K, where the intensity increased considerably.