TY  - JOUR
ID  - SisLab1798
UR  - http://dx.doi.org/10.1063/1.4914537
IS  - 17D122
A1  - T., A. Ho
A1  - T., D. Thanh
A1  - Yu, Yikyung
A1  - D., M. Tartakovsky3
A1  - T., O. Ho
A1  - Pham, Duc Thang
A1  - Le, Anh Tuan
A1  - Phan, The Long
A1  - S., C. Yu
Y1  - 2015///
N2  - The critical behavior of Pr1? x Ca x MnO3 samples with x?=?0.25, 0.27, and 0.29 has been investigated. Detailed analyses of magnetic-field dependences of magnetization at temperatures around the paramagnetic-ferromagnetic transition, M(H, T), reveal that the samples undergo a second-order magnetic phase transition. The Arrott plot method predicts the values of critical parameters to be T C????118?K, ??=?0.351?±?0.003, ??=?1.372?±?0.002, and ??=?4.90?±?0.02 for x?=?0.25; T C????116?K, ??=?0.362?±?0.002, ??=?1.132?±?0.004, and ??=?4.09?±?0.03 for x?=?0.27; and T C????110?K, ??=?0.521?±?0.002, ??=?0.912?±?0.005, and ??=?2.71?±?0.02 for x?=?0.29. The values of ??=?0.351 (for x?=?0.25) and ??=?0.362 (for x?=?0.27) are close to the value ??=?0.365 expected for the 3D Heisenberg model, proving an existence of short-range ferromagnetic interactions in these samples. A slight increase in Ca-doping content (x?=?0.29) leads to the shift of the ? value (=0.521) towards that of the mean-field theory (with ??=?0.5) characteristic of long-range ferromagnetic interactions. The samples also exhibit a magnetocaloric effect: around T C of Pr1? x Ca x MnO3 compounds, magnetic-entropy change reaches the maximum values of about 5.0, 4.1, and 2.5?J kg?1 K?1 for x?=?0.25, 0.27, and 0.29, respectively, under an applied-field change of 50 kOe. Magnetic-field dependences of the maximum magnetic-entropy change (?S max) obey a power law |?S max(H)| ? Hn , where exponent values n?=?0.68?0.74 are close to those obtained from the theoretical relation n?=?1?+?(????1)/(??+??).
T. A. Ho1, T. D. Thanh1,2, Yu3, D. M. , T. O. Ho4, P. D. Thang5, Anh-Tuan Le6, The-Long Phan1 and S. C. Yu
JF  - Journal Applied Physics
VL  - 117
TI  - Critical behavior and magnetocaloric effect of Pr1-xCaxMnO3
AV  - none
ER  -