A study of magnetocaloric effect in PrCo2Si2 to understand contributions to magnetoresistance

The results of electrical resistivity and heat capacity measurements in the presence of an external magnetic field on the compounds PrCo2Si2 and Pr0.8 La0.2Co2Si2 are reported. The magnetocaloric effect Delta T-ad (Delta H,T) is obtained from in-field heat capacity data. Comparison has been made betw een the temperature dependence of Delta T-ad and the change in resistance d ue to magnetic field Delta rho [= {rho(H) - rho(0)}] in both the compounds. The study indicates that Delta T-ad and -Delta rho have similar temperatur e dependence where Delta rho is predominantly due to the change in conducti on electron relaxation time, but it may be different if it is dominated by the change in carrier concentration. This observation indicates the importa nce of magnetocaloric studies to understand the major contributions to magn etoresistance. The studies also indicate that a large positive magnetoresis tance can be observed due to the appearance of a magnetic superzone gap wit h the application of an external magnetic field. (C) 2000 Published by Else vier Science Ltd. All rights reserved.