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Optimization of magnetic and transport properties of ultrathin films. In Fig. 1(a) is shown the temperature dependence of magnetization upon cooling down in magnetic field applied along the  direction before annealing (triangles) and after annealing (quadrats) of the 5 nm thick film grown on buffer. The inset demonstrates the dependence of the Curie temperature on the film thickness under different preparation conditions without barrier: before (filled circle) and after annealing (open circle) (i); grown on top of barrier: not annealed (triangles) and after annealing (quadrats) (ii). Figure 1(b) shows magnetoresistance dependences for and components in the metallic state taken at in the Hall geometry of for 5 nm thick films with optimized properties. Arrows indicate directions of the field sweep.
Dependence of resistance on temperature for and components upon cooling down without magnetic field. Arrows indicate positions of maximum of resistance near , minimum of resistance in the metallic state and temperature of the MIT. The inset demonstrates longitudinal conductivity vs dependence, where . Arrow indicates temperature of the MIT. Symbols A, B, and C in the inset mark regions with different transport behavior. The dependence follows the linear law , where ; , and ; for regions A (metallic) and region B (insulating), correspondingly.
Giant anisotropic magnetoresistance in with thickness 5 nm at temperature . Longitudinal component of resistance vs for different angles : 0°, 45°, and 90° between magnetic field and  direction [Fig. 3(a)]. Arrows indicate direction of the field sweep. Behavior of resistance reflects orientation of vector to crystallographic directions. In the remanent state magnetization is aligned along uniaxial easy axis . For applied along uniaxial hard axis vector of rotates and switches between two stable states with different resistance: the LR state—along uniaxial easy axis and the HR state along uniaxial hard axis. In Fig. 3(b) the angular dependence of the longitudinal resistance taken at is demonstrated.
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