Interface Ferromagnetism in (110)-Oriented La0.7Sr0.3MnO3/SrTiO3 Ultrathin Superlattices

TL;DR

This study demonstrates that (110)-oriented La0.7Sr0.3MnO3/SrTiO3 ultrathin superlattices maintain strong ferromagnetism down to four monolayers, with enhanced magnetic properties compared to (100) orientation, making them promising for spintronic applications.

Contribution

It reveals that (110)-oriented superlattices sustain robust ferromagnetism at ultrathin scales, outperforming (100) orientations in magnetic and metallic properties.

Findings

Ferromagnetism persists down to four monolayers.

(110) orientation shows stronger ferromagnetism than (100).

Superlattices exhibit near-saturation magnetic moments at >8 monolayers.

Abstract

We explore manganite interface magnetism in epitaxially grown La0.7Sr0.3MnO3(LSMO)/SrTiO3 ultrathin superlattices (SL) along (110) orientation. we show that robust ferromagnetism persists down to four monolayers LSMO(MLs) (~1.1 nm in thickness), of which 50% Mn is at the interface state. Above eight MLs, the magnetic moment is nearly saturated to the theoretical value of 3.7u_B, with an estimated interface moment of 3.2u_B. In comparison to (100)-oriented SLs which were previously shown to have a spin canted ground state, (110)-oriented SLs exhibit stronger low-dimensional ferromagnetism and better metallicity, suggesting a ferromagnetic interface spin state well suited for all-oxide spintronic devices. The underlining mechanism is qualitatively discussed.