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    Phase separation in rapid solidified Ag-rich Ag-Cu-Zr alloys
    (São Carlos : Universidade Federal de São Carlos, 2015) Niyomsoan, Saisamorn; Gargarella, Piter; Chomsaeng, Natthaphol; Termsuksawad, Preecha; Kühn, Utha; Eckert, Jürgen
    The microstructure and phase formation of rapid solidified Ag-rich Ag-Cu-Zr alloys were investigated. Two types of structure; interconnected- and droplet-type structures, were obtained due to phase separation mechanisms. The former was spinodal decomposition and the later was nucleation and growth mechanism. Depending on the alloy compositions, three crystalline phases; FCC-Ag, AgZr and Cu10Zr7 phases were observed along with an in-situ nanocrystalline/amorphous composite. Vickers hardness testing indicated a significant increase of hardness in the nanocrystalline/amorphous-composite alloy.
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    Phase transition and anomalous low temperature ferromagnetic phase in Pr 0.6Sr 0.4MnO 3 single crystals
    (New York, NY : Springer Science + Business Media B.V., 2009) Rößler, S.; Harikrishnan, S.; Naveen Kumar, C.M.; Bhat, H.L.; Elizabeth, S.; Rößler, U.K.; Steglich, F.; Wirth, S.
    We report on the magnetic and electrical properties of Pr 0.6Sr 0.4MnO 3 single crystals. This compound undergoes a continuous paramagnetic-ferromagnetic transition with a Curie temperature T C301 K and a first-order structural transition at T S64 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.