Effect of the self-organized cluster structure in LaSrMnO films on the slope of the temperature dependence of resistivity

Abstract

We have studied the effect of atomic ordering in a nanodimensional clustered structure of amorphous LaSrMnO films on the slope of the temperature dependence of resistivity ρ(T) in the regions where dρ/dT > 0. It is established that a high concentration of clusters of a “metallic” phase (C _met = 9%) capable of fertromagnetic ordering leads to a giant temperature coefficient of resistivity (TCR), with its value (normalized slope) reaching (dρ/dT)/ρ = 1.6 × 10⁴% K⁻¹. Samples with a small concentration of such clusters (C _met = 0.1%) possess paramagnetic properties and their normalized TCR decreases by three orders of magnitude to (dρ/dT)/ρ = 1.7 × 10¹% K⁻¹. This behavior is explained by self-consistent changes in the atomic, magnetic, and electron subsystems.