Intrinsic ferromagnetism in insulating cobalt doped anatase TiO2 -: art. no. 157204

被引:317
作者
Griffin, KA
Pakhomov, AB
Wang, CM
Heald, SM
Krishnan, KM [1 ]
机构
[1] Univ Washington, Dept Mat Sci & Engn, Seattle, WA 98195 USA
[2] Pacific NW Natl Lab, Fundamental Sci Div, Richland, WA 99352 USA
关键词
D O I
10.1103/PhysRevLett.94.157204
中图分类号
O4 [物理学];
学科分类号
0702 ;
摘要
Using complementary experiments we show that the room temperature ferromagnetism observed in anatase CoTiO2 films is not carrier mediated, but coexists with the dielectric state. TEM and x-ray absorption spectroscopy reveal a solid solution of Co in anatase, where Co is not metallic but in the +2 state substituting for Ti. Measurements at 300 K yield a M-S of 1.1 mu(B)/Co atom, while all films are highly insulating. The evidence of intrinsic ferromagnetism in the dielectric ground state of CoTiO2 leads to new considerations for the origin of ferromagnetism in transition metal doped oxides.
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页数:4
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