TY  - JOUR
ID  - SisLab1264
UR  - doi:10.1016/j.jallcom.2014.06.107
A1  - Phan, The Long
A1  - Ho, T.A
A1  - Pham, Duc Thang
A1  - Tran, Q.T
A1  - Tran, D. Thanh
A1  - Nguyen, X. Phuc
A1  - Phan, M. H
A1  - Bui, T. Huy
A1  - Yu, S.C.
Y1  - 2014///
N2  - We have determined the values of critical exponents of two polycrystalline samples (Nd1?xYx)0.7Sr0.3MnO3 (x = 0 and 0.07) from the magnetization data versus temperature and magnetic field, M(H, T), to learn about their magnetic and magnetocaloric (MC) properties. The results reveal the samples exhibiting the crossover of first-order and second-order phase transitions, where the exponent values ? = 0.271 and ? = 0.922 for x = 0, and ? = 0.234?0.236 and ? = 1.044?1.063 for x = 0.07 determined by using modified Arrott plots and static-scaling hypothesis are close to those expected for the tricritical mean-field theory (? = 0.25 and ? = 1.0). Particularly, the TC of x = 0 and 0.07 can be any value in the temperature ranges of 240?255 K and 170?278 K, respectively, depending on the magnitude of applied magnetic field and determination techniques. Around the TC, studying the MC effect of the samples has revealed a large magnetic-entropy change (?Sm) up to ?8 J/kg K for the applied field interval ?H = 50 kOe, corresponding to refrigerant capacity values of 200?245 J/kg. These phenomena are related to the crossover nature and the persisting of FM/anti-FM interactions even above the TC, as further confirmed by electron-spin-resonance data, Curie?Weiss law-based analyses, and an exponential parameter characteristic of magnetic order n = dLn|?Sm|/dLnH.
JF  - Journal of Alloys and Compounds
VL  - 615
SN  - 0925-8388
TI  - Critical Behavior of Y-doped Nd0.7Sr0.3MnO3 Manganites Exhibiting the Tricritical Point and Large Magnetocaloric Effect
SP  - 937
AV  - none
EP  - 945
ER  -