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arXiv · 2009.13185

Precise control of $J_\mathrm{eff}=1/2$ magnetic properties in Sr$_2$IrO$_4$ epitaxial thin films by variation of strain and thin film thickness

Stephan Geprägs·Björn Erik Skovdal·Monika Scheufele·Matthias Opel·Didier Wermeille·Paul Thompson·Alessandro Bombardi·Virginie Simonet·Stéphane Grenier·Pascal Lejay·Gilbert Andre Chahine·Diana Quintero Castro·Rudolf Gross·Dan Mannix
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Abstract

We report on a comprehensive investigation of the effects of strain and film thickness on the structural and magnetic properties of epitaxial thin films of the prototypal $J_\mathrm{eff}=1/2$ compound Sr$_2$IrO$_4$ by advanced X-ray scattering. We find that the Sr$_2$IrO$_4$ thin films can be grown fully strained up to a thickness of 108 nm. By using X-ray resonant scattering, we show that the out-of-plane magnetic correlation length is strongly dependent on the thin film thickness, but independent of the strain state of the thin films. This can be used as a finely tuned dial to adjust the out-of-plane magnetic correlation length and transform the magnetic anisotropy from two-dimensional (2D) to three-dimensional (3D) behavior by incrementing film thickness. These results provide a clearer picture for the systematic control of the magnetic degrees of freedom in epitaxial thin films of Sr$_2$IrO$_4$ and bring to light the potential for a rich playground to explore the physics of $5d$-transition metal compounds.

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Stephan Geprägs, Björn Erik Skovdal, Monika Scheufele, Matthias Opel, Didier Wermeille, Paul Thompson, Alessandro Bombardi, Virginie Simonet, Stéphane Grenier, Pascal Lejay, Gilbert Andre Chahine, Diana Quintero Castro, Rudolf Gross, Dan Mannix. 2020-09-28. Precise control of $J_\mathrm{eff}=1/2$ magnetic properties in Sr$_2$IrO$_4$ epitaxial thin films by variation of strain and thin film thickness. https://doi.org/10.1103/physrevb.102.214402

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