| We have conducted a systematic study of the light rare-earth diantimonide compounds, namely: (La-Nd, Sm) Sb2 . These compounds are interesting because of their low dimensionality, which leads to interesting phenomenon like the magnetic and resistive anisotropy reported previously [1]. Other properties include quantum oscillations, superconductivity, antiferromagnetism and metamagnetism [2].;We report results from specific heat, resistivity, magnetoresistance, and Hall effect measurements on these materials. Anomalies in transport measurements at various temperatures have been detected, consistent with previous reports of antiferromagnetism in PrSb2, NdSb2 and SmSb 2. These anomalies are related to cusps in heat capacity.;Warming and cooling curves did not reveal any hysteresis in Cp versus T, suggesting that these anomalies may be related to second order phase transitions. Similar transitions have been detected in CdeSb2. From the Cp versus T data we made an estimate of the electronic (gamma0), lattice (beta) and antiferromagnetic (deltaa) contributions to specific heat. We have managed to get reasonably good approximations for the Sommerfeld and beta coefficients of the nonmagnetic LaSb2. From these parameters as a first approximation, we have determined the Fermi energy and the Debye temperature of LaSb2 to be approximately 3.8 eV and 137 K respectively. These results on LaSb2 have been used comparatively to analyze the magnetic compounds. We have also calculated the entropy of the magnetic compounds. Our calculations of the entropy together with the specific heat measurements suggest that crystal electric field (CEF) effects occur in all of these materials with the exception of the nonmagnetic LaSb2. |
