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Disorder effects at low temperatures in La_{0.7-x}Y_{x}Ca_{0.3}MnO_{3} manganites

M. A. Gusmao·L. Ghivelder·R. S. Freitas·R. A. Ribeiro·O. F. de Lima·F. Damay·L. F. Cohen
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Abstract

With the aim of probing the effect of magnetic disorder in the low-temperature excitations of manganites, specific-heat measurements were performed in zero field, and in magnetic fields up to 9 T in polycrystalline samples of La_{0.7-x}Y_{x}Ca_{0.3}MnO_{3}, with Y concentrations x=0, 0.10, and 0.15. Yttrium doping yielded the appearance of a cluster-glass state, giving rise to unusual low-temperature behavior of the specific-heat. The main feature observed in the results is a strong enhancement of the specific-heat linear term, which is interpreted as a direct consequence of magnetic disorder. The analysis was further corroborated by resistivity measurements in the same compounds.

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M. A. Gusmao, L. Ghivelder, R. S. Freitas, R. A. Ribeiro, O. F. de Lima, F. Damay, L. F. Cohen. 2003-06-23. Disorder effects at low temperatures in La_{0.7-x}Y_{x}Ca_{0.3}MnO_{3} manganites. https://doi.org/10.1016/s0038-1098(03)00511-8

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