Defect-induced magnetism in TiO$_2$: An example of quasi 2D magnetic order with perpendicular anisotropy

TL;DR

This paper reviews how atomic lattice defects in TiO₂ induce room-temperature magnetic order with perpendicular anisotropy, highlighting the robustness and potential applications of defect-induced magnetism in nonmagnetic oxides.

Contribution

It provides a comprehensive review of experimental and theoretical findings on defect-induced magnetic order in TiO₂, emphasizing the formation of ultrathin magnetic layers with perpendicular anisotropy.

Findings

Magnetic order can be induced in TiO₂ by low-energy ion irradiation.

A stable ultrathin magnetic layer with perpendicular anisotropy is observed.

Room temperature magnetic response demonstrates robustness of defect-induced magnetism.

Abstract

Magnetic order at room temperature induced by atomic lattice defects, like vacancies, interstitials or pairs of them, has been observed in a large number of different nonmagnetic hosts, such as pure graphite, oxides and silicon-based materials. High Curie temperatures and time independent magnetic response at room temperature indicate the extraordinary robustness of this new phenomenon in solid state magnetism. In this work, we review experimental and theoretical results in pure TiO$_2$ (anatase), which magnetic order can be triggered by low-energy ion irradiation. In particular, we discuss the systematic observation of an ultrathin magnetic layer with perpendicular magnetic anisotropy at the surface of this oxide.