Low-temperature magnetoresistance of Nb-doped transparent conducting films

✍ Scribed by Xiao Wan Zheng; Zhi Qing Li

• Book ID: 104093904
• Publisher: Elsevier Science
• Year: 2010
• Tongue: English
• Weight: 714 KB
• Volume: 150
• Category: Article
• ISSN: 0038-1098
• DOI: 10.1016/j.ssc.2010.06.040

✦ Synopsis

The magnetoresistance of two anatase Nb-doped TiO 2 films has been measured. The samples reveal both negative and positive magnetoresistance component at all measuring temperatures. It is indicated that the Lorentz force effect based on a two-band model can describe the positive magnetoresistance contribution well. Rather than weak localization or Kondo effect, the negative magnetoresistance behaviors follow a semiempirical expression considering the effect of localized magnetic moments. This expression, due to Khosla and Fischer in a paper published 40 years ago [R.P. Khosla, J.R. Fischer, Phys. Rev. B 2 (1970) 4084], is deduced from the s-d exchange Hamiltonian by considering the third-order perturbation. The field dependence of the magnetization curves for both samples reveals ferromagnetic characteristics, which proves the existence of localized magnetic moment in Ti 1-x Nb x O 2 compounds.