Implication of local moment at Ti and Fe sites for the electrical and magneto-transport properties of degenerate semiconducting Ti₁-xFexO₂-d epitaxial films

J Phys Condens Matter. 2012 Feb 8;24(5):056004. doi: 10.1088/0953-8984/24/5/056004. Epub 2012 Jan 18.

Abstract

We have investigated the effect of local magnetic moment on the electrical and magneto-transport properties of thin films of the degenerate semiconductor Ti(1-x)Fe(x)O(2-d) (x = 0,0.04). The electrical measurements of these films reveal high temperature metallic behavior and resistivity minima. The behavior below the resistivity minimum temperature is ascribed to Kondo like scattering. The coupling between the local moment and the charge carriers is reflected in the magnetoresistance measurements in these films. This work indicates competition between the magnetic ordering mechanism by J(RKKY) and the moment screening mechanism by J(Kondo). Accordingly the role of carrier density in achieving the magnetic ordering in such materials either by defect engineering or by transition metal doping is discussed.