J. Appl. Phys. 113, 063911 (2013)

M. Ziese, F. Bern, and I. Vrejoiu

Abstract

The magnetization processes in Pr_0.7Ca0.3MnO₃/SrRuO₃ and La_0.7Sr_0.3MnO₃/SrRuO₃ superlattices
were studied. In both superlattices the ferromagnetic layers are antiferromagnetically coupled across
the interfaces. Whereas superlattice La_0.7Sr_0.3MnO₃/SrRuO₃ showed a three-step magnetization reversal mechanism for all temperatures, superlattice Pr_0.7Ca0.3MnO₃/SrRuO₃ had a compensation point with a two-step below and a three-step reversal mechanism above the compensation temperature. Exchange-bias and coercive fields, the vertical magnetization shift as well as the minor loop opening were measured as a function of the cooling field. Main findings were a change of the exchange-bias field from negative to positive values for increasing cooling fields in the two-step reversal regime and from negative values to zero for increasing cooling fields in the three-step reversal regime. Exchange-bias training occurs mostly within the first magnetization cycle. The data are consistent with the formation of interfacial domain walls.

DOI