Influence of structural disorder on magnetic and transport properties of (La0.7Sr0.3)0.5(Pr0.65Ca0.35)0.5MnO3 films
| Autor: | Junghum Park, Y. P. Lee, V. S. Flis, G. G. Kaminsky, V. G. Prokhorov, V. L. Svetchnikov |
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| Rok vydání: | 2005 |
| Předmět: | |
| Zdroj: | Low Temperature Physics. 31:161-167 |
| ISSN: | 1090-6517 1063-777X |
| Popis: | Magnetic and transport properties of (La0.7Sr0.3)0.5(Pr0.65Ca0.35)0.5MnO3 films prepared by a “co-deposition” utilizing the laser-ablation technique are investigated in a wide temperature range. The film deposited at 300 °C has a nanocrystalline disordered structure and exhibits a paramagnetic temperature dependence of the magnetization with a narrow peak (ΔT≃10 K) at TG≃45 K, which can be interpreted as a paramagnetic→superparamagnetic transition. A short-term annealing of the as-deposited film at 750 °C leads to the formation of a high-textured polycrystalline microstructure and to the appearance of ferromagnetic (FM) and metal–insulator (MI) transitions at TC≃240 K and TP≃140 K, respectively. The observed discrepancy between TP and TC values can be ascribed to a percolating nature of the MI transition, with an exponent of 5.3 for the percolating conductivity. The film deposited at Tsub≃740 °C is composed of lattice-strain-free and the lattice-strained crystallites with different lattice parameters and ... |
| Databáze: | OpenAIRE |
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