Correlation of structural and magnetic properties of RFeO3 ( R=Dy,Lu )

Abstract

In orthoferrites the rare-earth (R) ion has a big impact on structural and magnetic properties; in particular, the ionic size influences the octahedral tilt and the R3+−Fe3+ interaction modifies properties like the spin reorientation. Growth-induced strain in thin films is another means to modify materials properties since the sign of strain affects the bond length and therefore directly the orbital interaction. Our study focuses on epitaxially grown (010)-oriented DyFeO3 and LuFeO3 thin films, thereby investigating the impact of compressive lattice strain on the magnetically active Dy3+ and magnetically inactive Lu3+ compared to uniaxially strained single-crystal DyFeO3. The DyFeO3 films exhibits a shift of more than 20 K in spin-reorientation temperatures, maintain the antiferromagnetic Γ4 phase of the Fe lattice below the spin reorientation, and show double-step hysteresis loops for both in-plane directions between 5 and 390 K. This is the signature of an Fe-spin-induced ferromagnetic Dy3+ lattice above the Néel temperature of the Dy. The observed shift in the film spin reorientation temperatures vs lattice strain is in good agreement with isostatic single-crystal neutron diffraction experiments with a rate of 2 K/kbar. Published by the American Physical Society 2024