Temperature dependences of resistivity and magnetoresistivity for half-metallic ferromagnets

TL;DR

This paper investigates the temperature and magnetic field dependence of resistivity and magnetoresistivity in half-metallic ferromagnets, highlighting the role of non-quasiparticle states and different scattering regimes.

Contribution

It provides a theoretical analysis of resistivity behavior across different temperature regimes and discusses the impact of incoherent states on transport properties in half-metallic ferromagnets.

Findings

Resistivity scales as T^{9/2} below T* and T^{7/2} above T*

Non-quasiparticle states can dominate impurity resistivity and tunnel conductance

Magnetoresistance is influenced by the crossover temperature T*

Abstract

Peculiarities of transport properties of three- and two-dimensional half-metallic ferromagnets are investigated, which are connected with the absence of spin-flip scattering processes. The temperature and magnetic field dependences of resistivity in various regimes are calculated. The resistivity is proportional to T^{9/2} for T<T* and to T^{7/2} for T>T*, T* being the crossover temperature for longitudinal scattering processes. The latter scale plays also an important role in magnetoresistance. The contribution of non-quasiparticle (incoherent) states to the transport properties is discussed. It is shown that they can dominate in the temperature dependence of the impurity-induced resistivity and in the tunnel junction conductivity.