Correlation of Structural and Magnetic Properties of RFeO3 (R=Dy, Lu)

TL;DR

This study investigates how epitaxial strain affects the structural and magnetic properties of RFeO3 thin films, revealing significant shifts in spin reorientation temperatures and magnetic behaviors due to lattice strain.

Contribution

It provides new insights into the impact of epitaxial strain on magnetic phase transitions in RFeO3 thin films, especially for DyFeO3 and LuFeO3, with quantitative strain effects.

Findings

DyFeO3 films show a 20K shift in spin reorientation temperature.

Fe-spin induced ferromagnetism observed above Dy Néel temperature.

Strain effects on spin reorientation are consistent with neutron diffraction data.

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 20K in spin-reorientation temperatures, maintain the antiferromagnetic {\Gamma}4 phase of the Fe-lattice below the spin reorientation, and show double step hysteresis loops for both in-plane directions between 5 K and 390 K. This is the signature of an Fe-spin induced ferromagnetic Dy3+ lattice above the N\'eel 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 bar.