Intrinsic magnetocaloric effect at a first-order magnetic transition
Shenyang National Laboratory for Materials Science, Institute of Metal Research, and International Center for Materials Physics, Chinese Academy of Sciences - Shenyang 110016, PRC
Accepted: 24 January 2012
A four-parameter method has been developed to determine the magnetocaloric effect associated with a first-order magnetic transition. In order to prevent misevaluation due to the intrinsically irreversible features, the transition is mimicked by a reversible process. The magnetization and the isothermal magnetic-entropy change are shown to be dependent on only four intrinsic parameters, which can be easily obtained in experiments. A new method to calculate the magnetic-entropy change is derived, which is referred to as Landau approach. The four-parameter method as well as the Landau approach are demonstrated on the famous magnetocaloric material LaFe11.5Si1.5. They benefit from the experimental investigation of MCE very much and make the characterization of MCE much easier. This may be helpful for the search of better magnetocaloric materials.
PACS: 75.30.Sg – Magnetocaloric effect, magnetic cooling / 75.30.Kz – Magnetic phase boundaries (including classical and quantum magnetic transitions, metamagnetism, etc.) / 75.40.Cx – Static properties (order parameter, static susceptibility, heat capacities, critical exponents, etc.)
© EPLA, 2012