Dh. Lee et al., CHARACTERIZATION OF THE MAGNETIC-PROPERTIES AND TRANSPORT MECHANISMS OF COXFE3-XO4 SPINEL, Solid state communications, 96(7), 1995, pp. 445-449
CoxFe3-xO4 spinels were synthesized at 1100 degrees C in air and their
phases were investigated by XRD. In the IR spectra of these samples,
the stretching vibration of tetrahedral group was observed at 583cm(-1
), which means that the tetrahedral structure was not influenced by th
e concentration of Co ion. The cation distribution determined by Mossb
auer spectroscopy is closely related to the lattice parameter as well
as magnetic properties. From the measurements of the magnetic moment,
it has been known that the arrangement of magnetic moment between tetr
ahedral(A) and octahedral(B) site is canted in this spinel. The n-type
and p-type conductions were observed in the samples with x<1.0 and x=
1.2, respectively, showing that p-type to n-type transition occurred a
t 1140K in the sample of x=1.0. The n-type and p-type conductions are
due to the formation of Fe2+ ion and Co3+ ion forming Co2++Co4+ excito
n in B site.