7 January 2009 Nanostructured systems which exhibits a fairly large magnetoresistance near room temperature
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Proceedings Volume 7297, Advanced Topics in Optoelectronics, Microelectronics, and Nanotechnologies IV; 72970Y (2009) https://doi.org/10.1117/12.823645
Event: Advanced Topics in Optoelectronics, Microelectronics, and Nanotechnologies IV, 2008, Constanta, Romania
Abstract
In this paper we focus on a less-studied system La-Pb-Ca-Mn-O perovskite like manganite. Ca was introduced as partial substituent for Pb or as additive to the parent composition La0.6 Pb 0.4MnO3. The structure and magnetotransport properties of the polycrystalline manganites La0.6Pb0.4MnO3, La0.6Pb0.2Ca0.2MnO3 and La0.6Pb0.4Ca0.2MnO3 prepared by sol-gel self-combustion and heat treatment at 1000oC for 40 and 320 min were investigated. Measurements have been carried out in the temperature range 87 - 393 K on bulk samples. All manganites exhibit a peak in the resistivity around 175 - 225 K, well below TC (310 - 330 K). Magnetoresistance MR is negative, increases with decreasing temperature and exhibits a maximum at low temperature, 92 - 130 K, below the electrical transition temperature. Magnitude of MR at the peaks can attain 35% for Ca addition sample, La0.6 Pb0.4 Ca0.2MnO3, which has the largest resistivity. At room temperature, a smaller MR effect, of about 10%, is obtained. A longer heat treatment does not enhance the magnetoresistance at room temperature.
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C Doroftei, E. Rezlescu, N. Rezlescu, P. D. Popa, "Nanostructured systems which exhibits a fairly large magnetoresistance near room temperature", Proc. SPIE 7297, Advanced Topics in Optoelectronics, Microelectronics, and Nanotechnologies IV, 72970Y (7 January 2009); doi: 10.1117/12.823645; https://doi.org/10.1117/12.823645
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