abstract
We found that the anomalous magnetic entropy change peak obtained from magnetization measurements in some first-order magnetic phase transition materials may result from the usual data analysis procedure, which does not take into account magnetic irreversibility or mixed-phase regime. The deviations produced are comparable to anomalous effects discussed in the literature and may even exceed the theoretical limit. Our results show that this anomalous magnetic entropy change peak should not necessarily be interpreted as a consequence of the particular physics of the studied system. This also explains its absence in specific heat measurements.
keywords
TRANSITION; GD-5(SI2GE2)
subject category
Physics
authors
Amaral, JS; Amaral, VS
our authors
João Cunha de Sequeira Amaral
Auxiliary Researcher
Vitor Brás Sequeira Amaral
Full professorProjects
Research on Magnetic Oxides using Radioactive Isotopes at ISOLDE-CERN (POCI/FP/81979/2007)
Materials science and fundamental research on nano-stratified rare earth based compounds for magnetic refrigeration and sensor applications-Unusual martensitic transitions driven by the electronic fluid (POCI/CTM/61284/2004)
acknowledgements
We thank Dr. D. S. Schmool for a critical reading of the manuscript. We acknowledge the financial support from FCT (Project Nos. POCI/FP/81979/2007, POCI/CTM/61284/2004, and PhD Grant No. SFRH/BD/17961/2004).