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 Pr0.8La0.2Co2Si2 are reported. The magnetocaloric effect ΔTad (ΔH,T) is obtained from in-field heat capacity data. Comparison has been made between the temperature dependence of ΔTad and the change in resistance due to magnetic field Δρ [={ρ(H)−ρ(0)}] in both the compounds. The study indicates that ΔTad and −Δρ have similar temperature dependence where Δρ is predominantly due to the change in conduction electron relaxation time, but it may be different if it is dominated by the change in carrier concentration. This observation indicates the importance of magnetocaloric studies to understand the major contributions to magnetoresistance. The studies also indicate that a large positive magnetoresistance can be observed due to the appearance of a magnetic superzone gap with the application of an external magnetic field.