Emergent magnetism with continuous control in the ultrahigh conductivity layered oxide PdCoO2

TL;DR

This paper demonstrates that ferromagnetism can be externally and continuously controlled in the ultra-high conductivity layered oxide PdCoO2 through helium implantation and annealing, enabling tunable magnetic and transport properties for spintronics.

Contribution

It introduces a method to reversibly induce and erase ferromagnetism in PdCoO2 by targeting magnetic metastability via helium implantation and annealing, with potential for precise magnetic control.

Findings

Helium implantation induces local lattice distortions and magnetic moments.

These moments communicate through itinerant electrons to establish ferromagnetism.

Magnetic states can be reversibly tuned by annealing, enabling continuous control.

Abstract

The current challenge to realizing continuously tunable magnetism lies in our inability to systematically change properties such as valence, spin, and orbital degrees of freedom as well as crystallographic geometry. Here, we demonstrate that ferromagnetism can be externally turned on with the application of low-energy helium implantation and subsequently erased and returned to the pristine state via annealing. This high level of continuous control is made possible by targeting magnetic metastability in the ultra-high conductivity, non-magnetic layered oxide PdCoO2 where local lattice distortions generated by helium implantation induce emergence of a net moment on the surrounding transition metal octahedral sites. These highly-localized moments communicate through the itinerant metal states which triggers the onset of percolated long-range ferromagnetism. The ability to continuously tune competing interactions enables tailoring precise magnetic and magnetotransport responses in an ultra-high conductivity film and will be critical to applications across spintronics.