Magnetic and structural properties of the CeCo1-xCuxAl4 (x=0, 0.05, 0.1) compounds

We report on the neutron diffraction, magnetic susceptibility, specific heat and electrical resistivity studies of the antiferromagnetic CeCo1-xCuxAl4 (x = 0, 0.05, 0.1) compounds. The substitution of the Co atoms by Cu aims to highlight the influence of the impurity phases on the structure stability and on the magnetic properties. For x = 0.1, 0.05 and 0 the magnetic moments of 0.76, 0.74 and 0.69 mu(B)/Ce have been obtained, respectively. The phase transitions observed in the specific heat measurements suggest a presence of a small contribution of the CeCuAl3 and CeAl2 phases. The addition of Cu develops a small amount of the former phase and decreases strongly the amount of any other impurities stabilizing, therefore, the main CeCoAl4 phase. The neutron diffraction below the Neel temperature of 13.5 K confirms most of the previous studies on the magnetic structure of CeCoAl4.