arXiv subjects

Sachin B. Gupta

Publications and source records attributed to Sachin B. Gupta.

3 recordsLinked to original sources

arXiv2013

Change in the order of magnetic transition in HoRhGe as probed by magnetoresistance and magnetocaloric studies

Magnetoresistance and magnetocaloric properties of polycrystalline HoRhGe have been studied. This compound orders antiferromagnetically with a Neel temperature (TN) of 5.5 K and undergoes a first order metamagnetic transition at 2 K. It shows a large negative magnetoresistance of 25% at TN, for a field of 50 kOe. However, at 2 K and in lower fields, the magnetoresistance is found to be positive with a magnitude of about 12%, which is attributed to the first order metamagnetic transition. The compound also shows large magnetocaloric effect near its Neel temperature. Field dependence of magnetic entropy change also reflects the change in the nature of magnetic transition as the field is increased. The value of magnetic entropy change (-ΔSM) is found to be 11.1 J/kg K for a field change of 50 kOe. Field dependence of magnetoresistance and magnetocaloric effect clearly shows the change in the order of the metamagnetic transition with increase in field.

cond-mat.str-el↗

arXiv2013

Magnetic, magnetocaloric and transport properties of HoRuSi compound

Magnetic, thermal, magnetocaloric and transport properties of polycrystalline HoRuSi have been studied. It was found that the compound shows magnetic transitions at T1=18 K and T2=8 K. Magnetization data reveal that the ferromagnetic ordering is dominant in this compound. Magnetocaloric effect has been estimated from M-H-T data and the -ΔSM has been found to be 12.8 J/kg K for field of 50 kOe, which is comparable to some potential refrigerant materials in same temperature regime.

cond-mat.str-el↗

arXiv2012

Magnetic, magnetocaloric and magnetotransport properties of RSn_{1+x}Ge_{1-x} compounds (R=Gd, Tb, Er; x=0.1)

We have studied the magnetic, magnetocaloric and magnetotransport properties of RSn1+xGe1-x(R=Gd, Tb, Er; x=0.1) series by means of magnetization, heat capacity and resistivity measurements. It has been found that all the compounds crystallize in the orthorhombic crystal structure described by the centrosymmetric space group Cmcm (No. 63). The magnetic susceptibility and heat capacity data suggest that all the compounds are antiferromagnetic. Large negative values of θp in case of GdSn1.1Ge0.9 and TbSn1.1Ge0.9 indicate that strong antiferromagnetic interactions are involved, which is also reflected in the magnetization isotherms. On the other hand ErSn1.1Ge0.9 shows weak antiferromagnetic interaction. The heat capacity data have been analyzed by fitting the temperature dependence and the values of θD and γ have been estimated. Among these three compounds, ErSn1.1Ge0.9 shows considerable magnetic entropy change of 9.5 J/kg K and an adiabatic temperature change of 3.2 K for a field of 50 kOe. The resistivity data in different temperature regimes have been analyzed and the dominant contributions have been identified. All the compounds show small but positive magnetoresistance.

cond-mat.str-el↗