Tailoring the electronic properties of SrRuO3 films in SrRuO3/LaAlO3 superlattices

TL;DR

This study investigates how varying the thickness of SrRuO3 layers in SrRuO3/LaAlO3 superlattices affects their electronic and magnetic properties, revealing a tunable metal-insulator transition and ferromagnetism in ultrathin layers.

Contribution

It demonstrates the control of electronic phases in superlattices through layer thickness and strain, and introduces field effect devices based on these multilayer structures.

Findings

Reduced SRO layer thickness induces a metal-insulator transition.

All superlattices remain ferromagnetic at low temperatures.

Field effect devices can be fabricated using these multilayer structures.

Abstract

The electronic properties of SrRuO3/LaAlO3 (SRO/LAO) superlattices with different interlayer thicknesses of SRO layers were studied. As the thickness of SRO layers is reduced, the superlattices exhibit a metal-insulator transition implying transformation into a more localized state from its original bulk metallic state. The strain effect on the metal-insulator transition was also examined. The origin of the metal-insulator transition in ultrathin SRO film is discussed. All the superlattices, even those with SRO layers as thin as 2 unit cells, are ferromagnetic at low temperatures. Moreover, we demonstrate field effect devices based on such multilayer superlattice structures.