Magnetic phase transition of gadolinium studied by acoustically detected magnetocaloric effect

Abstract

This article reports on an investigation of the ferromagnetic to paramagnetic phase transition of gadolinium by means of a novel acoustic detection technique of magnetically induced temperature oscillations. Equations are derived for the magnetocaloric signal at the fundamental frequency of the magnetic field oscillation as well as for the second harmonic of the signal in terms of the temperature derivatives of the magnetization and of the susceptibility and specific heat capacity at constant magnetic field. Experimental data for three samples of different quality are analyzed with the theoretically derived equations and qualitatively compared with the linear model for critical behavior.