Relationship between hysteretic behavior of magnetization and magnetoresistance in half-metallic ferromagnets

A generalized Preisach description of hysteretic magnetotransport properties of half-metallic ferromagnets (HMFs) is proposed. Assuming that the system consists of an assembly of elementary bistable hysterons distributed in energy levels and with a range of possible energy barriers, the connection between irreversible magnetic and transport properties of HMFs is found. Within this model, both the magnetization hysteresis and resistivity hysteresis of HMFs can be described by a few simple assumptions common to description of hysteresis phenomena leading to some fundamental relationship.

Figure 1

Two magnetic hysterons $(h_{Ai},h_{Bi})$ and $(h_{Aj},h_{Bj})$ produce conductivity hysteron. Conductivity hysteron has two states with minimum and maximum conductivity with the switching fields coinciding with the magnetic hysteron.

Figure 2

(Color online) (a) Magnetization as a function of magnetic field curves constructed using classical Preisach model. (b) Resistivity as a function of magnetic field curves constructed using the proposed model. The following parameters for (a) and (b) were taken: ${\sigma }_C=300$, ${\sigma }_I=300$, ${\overline{h}}_C=100$, and the Preisach function was properly normalized. (c) Experimental resistivity as a function of magnetic field measured on ${\mathrm{La}}_{0.7}{\mathrm{Sr}}_{0.3}{\mathrm{MnO}}_3$ samples at $77\mathrm{K}$ (Ref. 17).