Spin-glass behavior and exchange bias in phase-separated Nd0.85Sr0.15CoO3

The magnetic properties of Nd0.85Sr0.15CoO3 have been systematically investigated by dc magnetization, ac susceptibility and magnetic relaxation. The dynamics scaling analysis of ac susceptibility and magnetic relaxation give sufficient evidence of the existence of a spin-glass phase, which can be ascribed to the complicated interactions among Co3+ and Co4+ ions in this phase-separated compound. The field-cooled magnetic hysteresis loop displays both horizontal and vertical shifts, i.e., the exchange bias effect, while no shifts are present with increase of the measuring field up to ±50 kOe. The results further sustain the picture of the spin-glass phase coexisting with other magnetic regions in the sample.

Research highlights
► Spin glassy behavior is observed in the phase-separated Nd0.85Sr0.15CoO3.
► The field-cooled magnetic hysteresis loop also displays the exchange bias effect.
► The spin-glass phase coexists with other magnetic regions in the sample.
► These phenomena can be explained by the interactions among Co3+ and Co4+ ions.