Propiedades magnéticas del sistema de aleaciones CuAl$_{1 - x}$Cr$_{x}$S$_{2}$ (x = 0.50, 0.75)

Abstract

The synthesis, structural characterization and magnetic properties of alloy system CuAl$_{1 - x}$Cr$_{x}$S$_{2}$ (x = 0.50, 0.75) are reported. The samples were synthesized by using the direct fusion technique. The chemical analysis (EDX) confirmed the stoichiometric ratio for the concentrations. The powder diffraction patterns were indexed and the principal phases crystallizes with tetragonal symmetry with unit cell parameters\linebreak $a$ = 5.312(1) {\AA}, $c$ = 10.389(2) {\AA} for x = 0.50 and $a$ = 5.314(2) {\AA}, $c$ = 10.393(2) {\AA} for x = 0.75. Theses alloys behave as antiferromagnetic, with Néel temperatures of 37 K and 39 K, respectively. The EPR linewidth for these alloys shows a paramagnetic behavior between 100 and 610 K.The resonance field and the g factor show a slight variation with temperature. These results are discussed in terms of nearest-neighbor Cr$^{ + 3}$ (S=3/2) spin-coupled pairs.