Intrinsic ferromagnetism in insulating cobalt doped anatase TiO2.
Using complementary experiments we show that the room temperature ferromagnetism observed in anatase Co:TiO(2) 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 Co:TiO(2) leads to new considerations for the origin of ferromagnetism in transition metal doped oxides.
Griffin
K A
KA
Department of Materials Science and Engineering, University of Washington, Seattle, Washington 98195, USA.
Pakhomov
A B
AB
Wang
C M
CM
Heald
S M
SM
Krishnan
Kannan M
KM