Magnetovolume effects on the GdNi/sub 1-x/Cu/sub x/ compounds with low magnetocrystalline anisotropy

摘要

Thermal expansion of GdNi/sub 1-x/Cu/sub x/ (x=0, 0.3 and 0.6) and the non magnetic LaNi and YNi strain gauge technique. Although changes in the crystalline and magnetic structures occur for x/spl ges/0.25 and x/spl ges/0.35 respectively, all the compounds show positive spontaneous volume magnetostriction. Combining thermal expansion and specific heat measurements we extract the pressure derivative of the ordering temperature. The relation between the magnetic thermal expansion coefficients and the derivative of the magnetic electrical resistivity is analysed, revealing different behaviours for the ferromagnetic and antiferromagnetic compounds.