Unconventional transport properties of the itinerant ferromagnet EuTi_1−xNb_xO₃(x=0.10–0.20)

Abstract

The detailed analysis of resistivity (ρ) for single-crystalline EuTi_1−xNb_xO₃(x=0.10–0.20), an itinerant ferromagnet with very low Curie temperature (T C), reveals that the charge conduction in this system is extremely sensitive to Nb concentration and dominated by several scattering mechanisms. Well below T C, where the spontaneous magnetization follows Bloch's T 3/2 law, ρ exhibits T 2 dependence with a large coefficient (∼ 10− 1 μ Ω cm K− 2) due to the electron-magnon scattering. Remarkably, all the studied samples exhibit a unique resistivity minimum at T= T min, below which ρ shows a logarithmic increment with T (for T C< T< T min) due to the Kondo scattering of 4 d 1 itinerant electrons of Nb by the localized 4 f moments of Eu 2+ which suppresses strongly with applied magnetic field.