Spin Seebeck Effect and Exchange Bias in LaFeO₃ Thin Films

In recent years, spin (magnon) swapping and longitudinal spin Seebeck effect have been observed in the canted antiferromagnetic insulator LaFeO₃ bulk single crystal [1-3]. In this work, LaFeO₃ epitaxial thin films were grown on the LaAlO₃(110) and SrTiO₃(100) single crystal substrates via off-axis radio-frequency magnetron sputtering. We observed the longitudinal spin Seebeck effect in the LaAlO₃(110)/LaFeO₃/Pt heterostructure. Furthermore, we investigated the exchange bias in the SrTiO₃(100)/LaFeO₃/Ni₈₁Fe₁₉ bilayer through the anomalous Nernst effect under vertical temperature gradient and in-plane field after field-cooling. As the temperature decreases, the exchange bias field has a maximum around 160 K and then decreases. This unusual behavior indicates the special antiferromagnetic configuration of LaFeO₃ thin film at the interface to the Ni₈₁Fe₁₉ at low temperatures.

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