La-deficient La0.54Ca0.32MnO3-??, Magnetic-entropy change Oxidation Ratio Mn3+ /Mn4+ Saturation moment
Issue Date:
2003
Publisher:
Journal of Magnetism and Magnetic Materials
Citation:
Volume 262, Issue 3, Page 502-507
Abstract:
A La-deficient sample of La0.54Ca0.32MnO3-?? was prepared by the solid-state reaction method.
The Curie temperature TC equals 300 K, which is significantly higher than those of the La1-xCaxMnO3-??
system. The magnetic-entropy change reaches a maximum value of -??SM ?? 5.5 J/kg K at the Curie
temperature upon a 5 T magnetic field variation. A saturation magnetic moment ?S = 2.99 ?B/f.u. at 5 K has
been derived from the magnetization data. Values of 0.0230 and 0.441 for the oxygen deficiency ?? and the
ratio of Mn3+/Mn4+, respectively, have been determined. From our study, it is suggested that this
compound is a suitable candidate for application as a working substance in magnetic refrigeration. ?? 2003
Elsevier Science B.V. All rights reserved.
