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キーワード:
Manganites; Phase separation
要旨:
We report on the magnetic and electrical properties of Pr0.6Sr0.4MnO3 single crystals. This compound undergoes a continuous paramagnetic-ferromagnetic transition with a Curie temperature T (C)301 K and a first-order structural transition at T (S)64 K. At T (S), the magnetic susceptibility exhibits an abrupt jump, and a corresponding small hump is seen in the resistivity. The critical behavior of the static magnetization and the temperature dependence of the resistivity are consistent with the behavior expected for a nearly isotropic ferromagnet with short-range exchange belonging to the Heisenberg universality class. The magnetization (M-H) curves below T (S) are anomalous in that the virgin curve lies outside the subsequent M-H loops. The hysteretic structural transition at T (S) as well as the irreversible magnetization processes below T (S) can be explained by phase separation between a high-temperature orthorhombic and a low-temperature monoclinic ferromagnetic phase.
