Evidence of metastability near the Curie temperature of polycrystalline gadolinium

Abstract

The adiabatic temperature change (ΔT) during the magnetization and demagnetization processes of bulk gadolinium is directly measured for several applied magnetic fields in the temperature range 285K to 305K. In low magnetic fields, the measurements of ΔT display two maxima at 293.8K and 291.5K with an inflection point between 289K and 293K. The height of the second peak is more pronounced at low applied magnetic fields and diminishes in high fields. The occurrence of a second ΔT maximum is indicative of the complex spin dynamics in Gd and is related to the presence of metastable states near the Curie temperature. © 2012 American Institute of Physics.