Heat capacity and magnetoresistance in Dy(Co,Si)(2) compounds

Abstract

Magnetocaloric effect and magnetoresistance have been studied in Dy(Co1-xSx)(2) (x=0, 0.075, and 0.15) compounds. Magnetocaloric effect has been calculated in terms of adiabatic temperature change (Delta T-ad) as well as isothermal magnetic entropy change (Delta S-M) using the heat-capacity data. The maximum values of Delta S-M and Delta T-ad for DyCo2 are found to be 11.4 JKg(-1) K-1 and 5.4 K, respectively. Both Delta S-M and Delta T-ad decrease with Si concentration, reaching values of 5.4 JKg(-1) K-1 and 3 K, respectively for x=0.15. The maximum magnetoresistance is found to be about 32% in DyCo2, which decreases with increase in Si. These variations are explained on the basis of itinerant electron metamagnetism occurring in these compounds. (c) 2005 American Institute of Physics.