Transport properties of CrO2 (110) films grown on TiO2 buffered Si substrates by chemical vapor deposition

Abstract

Epitaxial CrO2 (110)-oriented films were fabricated on Si (100) substrates buffered by rutile TiO2 derived from oxidation of a pulsed-laser-deposited TiN layer. The epitaxial films of CrO2 were prepared by chemical vapor deposition in a two-zone furnace with oxygen flow from a CrO3 precursor. The transport measurements show that the CrO2 films are metallic with a Curie temperature of about 380 K. The temperature dependence of resistivity was best described by a phenomenological expression ρ(T)=ρ0+AT2e(−Δ/T) over the range of 5–350 K with Δ=94 K. The magnetic measurements show the in-plane coercive fields are about 30 and 60 Oe at 300 and 5 K, respectively. The temperature dependent spontaneous magnetization follows Bloch’s T3/2 law and the slope suggests a critical wavelength of λΔ∼30.6 Å beyond which spin-flip scattering becomes important.