Página Inicial CNEA Laboratorio TANDAR Página Inicial TANDAR Historia del acelerador TANDAR Web interno Web mail
Inicio » Actividades I+D > Publicaciones 2012 > Direct observation of magnetocaloric eff...
acta de conferencia
"Direct observation of magnetocaloric effect by differential thermal analysis: influence of experimental parameters"
Y. Rotstein Habarnau, P. Bergamasco, J. Sacanell, G. Leyva, C. Albornoz and M. Quintero
Proc. of the "Frontiers of Condensed Matter V" (FCM 2010), Buenos Aires, Argentina, December 6-10, 2010. Ed. A.M. Llois and J.Guevara
Physica B Condens. Matter. 407(16) (2012) 3305-3307
Abstract
The magnetocaloric effect is the isothermal change of magnetic entropy and the adiabatic temperature change induced in a magnetic material when an external magnetic field is applied. In this work, we present an experimental setup to study this effect in metamagnetic transitions, using the differential thermal analysis technique, which consists in measuring simultaneously the temperatures of the sample of interest and a reference one while an external magnetic field ramp is applied. We have tested our system to measure the magnetocaloric effect in La0.305Pr0.32Ca0.375MnO3, which presents phase separation effects at low temperatures (T<200 K). We obtain ΔT vs H curves, and analyze how the effect varies by changing the rate of the magnetic field ramp. Our results show that the intensity of the effect increases with the magnetic field change rate. We also have obtained the effective heat capacity of the system without the sample by performing calorimetric measurements using a pulse heat method, fitting the temperature change with a two tau description. With this analysis, we are able to describe the influence of the environment and subtract it to calculate the adiabatic temperature change of the sample.
DEPARTAMENTO FISICA DE LA MATERIA CONDENSADA
Contacto
Av. Gral Paz y Constituyentes, San Martín, Pcia. de Buenos Aires, Argentina
Tel: (54-11) 6772-7007 - Fax: (54-11) 6772-7121