Exchange bias tuned by cooling field in phase separated Y0.2Ca0.8MnO3

Abstract

The effect of cooling field $H_{\mathrm{FC}}$ on the exchange bias field $H_{\mathrm{EB}}$ in a spontaneous lamellar ferromagnetic/antiferromagnetic phase separated ${\mathrm{Y}}_{0.2}{\mathrm{Ca}}_{0.8}\mathrm{Mn}{\mathrm{O}}_3$ has been studied. It is found that with increasing $H_{\mathrm{FC}}$ from $1\text{to}6\mathrm{T}$ the value of $H_{\mathrm{EB}}$ decreases by 37% at $2\mathrm{K}$ and is inversely proportional to the ferromagnetic layer thickness $t_{\mathrm{FM}}$ . This suggests that the tuning of $H_{\mathrm{EB}}$ by $H_{\mathrm{FC}}$ in ${\mathrm{Y}}_{0.2}{\mathrm{Ca}}_{0.8}\mathrm{Mn}{\mathrm{O}}_3$ arises from the variation of $t_{\mathrm{FM}}$ with $H_{\mathrm{FC}}$ . This phenomenon is essentially different from other types of magnetic tunings.