Magnetism in hafnium dioxide

Autor: Lucio Strazzabosco Dorneles, J. M. D. Coey, Munuswamy Venkatesan, C. B. Fitzgerald, Plamen Stamenov
Rok vydání: 2005
Předmět:
Zdroj: Physical Review B. 72
ISSN: 1550-235X
1098-0121
DOI: 10.1103/physrevb.72.024450
Popis: PUBLISHED
Thin films of HfO2 produced by pulsed-laser deposition on sapphire, yttria-stabilized zirconia, or silicon substrates show ferromagnetic magnetization curves with little hysteresis and extrapolated Curie temperatures far in excess of 400 K. The moment does not scale with film thickness, but in terms of substrate area it is typically in the range 150?400 ?B nm?2. The magnetization exhibits a remarkable anisotropy, which depends on texture and substrate orientation. Pure HfO2 powder develops a weak magnetic moment on heating in vacuum, which is eliminated on annealing in oxygen. Lattice defects are the likely source of the magnetism.
This work was supported by the Science Foundation of Ireland. We are grateful to Professor James Lunney for the use of his Pulsed Laser Deposition facilities, and to M. Kamino and Yang Zhou for the TEM and AGFM measurements, respectively. We have benefited from useful comments from G. A. Sawatzky and N. Krasnikova. L. S. Dorneles was supported by the Irish Research Council for Science Engineering and Technology IRCSET .
Databáze: OpenAIRE