Materials Science

Magnetic Titanium

See allHide authors and affiliations

Science  28 Jun 2013:
Vol. 340, Issue 6140, pp. 1501
DOI: 10.1126/science.340.6140.1501-c

The interface of SrTiO3 and LaAlO3 has puzzled physicists for some time now—it is not only highly conductive (and under certain circumstances even superconducting), it also exhibits magnetism even though neither of the two oxides is magnetic. Various explanations have been proposed for this unexpected magnetism, ranging from the presence of magnetic impurities or defects to an intrinsic property of the interface. Lee et al. used chemical-element–specific spectroscopic techniques to pinpoint the “host” of the magnetism. The analysis of the spectra indicated that the magnetic moments responsible for the magnetism were lying in the plane of the interface and were carried by Ti atoms, whereas comparison with calculations revealed similarities with spectra expected for the Ti valence state of Ti. Furthermore, varying the thickness of the LaAlO3 overlayer indicated that the Ti magnetic moments were located at the interface. Taken together, these results lend support to the intrinsic origin of the magnetism at the interface, although the role of, for example, oxygen defects cannot be entirely excluded.

Nat. Mater. 10.1038/nmat3674 (2013).

Navigate This Article