Exchange bias and memory effect in double perovskite Sr <inf>2</inf>FeCoO <inf>6</inf>

We report on the observation of exchange bias (EB) and memory effect in double perovskite Sr 2 FeCoO 6. Antiphase boundaries between the ferromagnetic and the antiferromagnetic regions in the disordered glassy phase are assumed as responsible for the observed effect, which reflects in the cooling field dependence and temperature evolution of exchange bias field and in training effect. The spin glass (SG) phase itself is characterized through memory, ageing, and magnetic relaxation experiments. The spin glass transition temperature, T g, versus H dc2/3 follows the Almeida-Thouless line yielding a freezing temperature, T f = 73 K. Time-dependent magnetic relaxation studies reveal the magnetization dynamics of the underlying glassy phase in this double perovskite. © 2012 American Institute of Physics.