Magnetic properties of (Ce1-xLax)PdIn2

We report on results of X-ray powder diffraction, magnetization and specific heat measurements of the pseudo-ternary (Ce1-xLax)PdIn2 system with x=0; 0.2; 0.4 and 0.6. The results show a linear increase of the unit cell volume and a reduction of the ferromagnetic transition as La content increases. The Debye temperature, Sommerfeld coefficient and crystal field parameters were estimated from specific heat data, and are found to be weakly dependent of the Ce concentration. Also, the variation of magnetic entropy at TC is only weakly dependent on x (ΔS≅0.92Rln2) indicating that TK/TC is approximately constant along the series. The TC and TK behaviors are explained by the variation of the exchange parameter due to the volume change when Ce is replaced by La. Our results indicate that the chemical pressure is the dominant effect rather than the chemical disorder for determining the physical proprieties of the (Ce1-xLax)PdIn2 system.