Dimensionality Engineering of Magnetic Anisotropy from Anomalous Hall Effect in Synthetic SrRuO3 Crystals

TL;DR

This study demonstrates how the dimensionality of epitaxially-grown correlated oxides influences magnetic anisotropy, revealing a significant enhancement in coercive field and systematic modulation of anisotropy through engineered heterostructures.

Contribution

We introduce a method to engineer magnetic anisotropy in synthetic SrRuO3 crystals by controlling dimensionality and heterostructure design, advancing spintronic material development.

Findings

1500% increase in coercive field for 3-unit-cell layers

Systematic modulation of anisotropy via lattice and orbital hybridization

Enhanced magnetic anisotropy explained by atomic-scale heterostructure analysis

Abstract

Magnetic anisotropy in atomically thin correlated heterostructures is essential for exploring quantum magnetic phases for next-generation spintronics. Whereas previous studies have mostly focused on van der Waals systems, here, we investigate the impact of dimensionality of epitaxially-grown correlated oxides down to the monolayer limit on structural, magnetic, and orbital anisotropies. By designing oxide superlattices with a correlated ferromagnetic SrRuO3 and nonmagnetic SrTiO3 layers, we observed modulated ferromagnetic behavior with the change of the SrRuO3 thickness. Especially, for three-unit-cell-thick layers, we observe a significant 1,500% improvement of coercive field in the anomalous Hall effect, which cannot be solely attributed to the dimensional crossover in ferromagnetism. The atomic-scale heterostructures further reveal the systematic modulation of anisotropy for the lattice structure and orbital hybridization, explaining the enhanced magnetic anisotropy. Our findings provide valuable insights into engineering the anisotropic hybridization of synthetic magnetic crystals, offering a tunable spin order for various applications.