화학공학소재연구정보센터
Current Applied Physics, Vol.11, No.3, 830-833, 2011
Critical behavior and magnetic entropy change in La0.7Ca0.3Mn0.9Zn0.1O3 perovskite manganite
We studied the critical behavior and magnetic entropy change in a perovskite-manganite compound of La0.7Ca0.3Mn0.9Zn0.1O3 around its Curie temperature of T-C = 206.75 K. Experimental results revealed that the sample exhibited the second-order magnetic phase transition with the exponents beta = 0.474 and gamma = 1.152 close to those expected from the mean-field theory (beta = 0.5 and gamma = 1.0). In the vicinity of T-C. the magnetic entropy change Delta S-M reached maximum values of 1.1, 1.7, and 2.7 J/kg K under magnetic-field variations of 10, 20, and 35 kOe, respectively. These Delta S-M values are much lower than those reported previously on the parent compound of La0.7Ca0.3MnO3. The nature of this phenomenon is discussed by means of the characteristics of the magnetic phase transition, and critical exponents. (c) 2010 Elsevier B.V. All rights reserved.