Abstract
Single-phase La2 (1-x) Co2x O3-δ polycrystalline samples with x=0%-8% were synthesized by the conventional ceramic method, and the effect of Co content on the magnetic behaviors has been systemically investigated. X-ray diffraction and x-ray photoelectron spectroscopy studies indicate no Co metal clusters or secondary magnetic phases in any samples in this study. It is found that the undoped or slightly doped samples show no ferromagnetic signal, while samples with x in the range of 0.5%-2% exhibit an exponential increase of saturation magnetization (Ms) as a function of Co concentration. When x increases beyond 2%, an inverse correlation between the magnetization and Co content was observed. We reported an Ms as large as 0.05 emug and a Curie temperature above RT in our samples, rendering Co: La2 O3 a candidate diluted magnetic oxide for RT applications. Our results also strongly support the oxygen vacancy (F -center) mediated mechanism for RT ferromagnetism in transition-metal doped high- k oxides
Original language | English (US) |
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Article number | 07D120 |
Journal | Journal of Applied Physics |
Volume | 103 |
Issue number | 7 |
DOIs | |
State | Published - 2008 |
Externally published | Yes |
ASJC Scopus subject areas
- General Physics and Astronomy