Reversal of Anomalous Hall Effect and Octahedral Tilting in SrRuO3 Thin Films via Hydrogen Spillover

The perovskite SrRuO3 (SRO) is a strongly correlated oxide whose physical and structural properties are strongly intertwined. Notably, SRO is an itinerant ferromagnet that exhibits a large anomalous Hall effect (AHE) whose sign can be readily modified. Here, a hydrogen spillover method is used to tailor the properties of SRO thin films via hydrogen incorporation. It is found that the magnetization and Curie temperature of the films are strongly reduced and, at the same time, the structure evolves from an orthorhombic to a tetragonal phase as the hydrogen content is increased up to approximate to 0.9 H per SRO formula unit. The structural phase transition is shown, via in situ crystal truncation rod measurements, to be related to tilting of the RuO6 octahedral units. The significant changes observed in magnetization are shown, via density functional theory (DFT), to be a consequence of shifts in the Fermi level. The reported findings provide new insights into the physical properties of SRO via tailoring its lattice symmetry and emergent physical phenomena via the hydrogen spillover technique.

Automated summary

This study uses the hydrogen spillover method to tailor the properties of SrRuO3 thin films by incorporating hydrogen. It is found that the magnetization and Curie temperature of the films are significantly reduced, and the structure evolves from an orthorhombic to a tetragonal phase with increasing hydrogen content. In situ crystal truncation rod measurements show that the structural phase transition is related to tilting of the RuO6 octahedral units. Density functional theory analysis demonstrates that the significant changes in magnetization result from shifts in the Fermi level. These findings provide new insights into the physical properties of SrRuO3 through the modulation of its lattice symmetry and emergent physical phenomena using the hydrogen spillover technique.