Structure and magnetic properties of Sm‐Ni‐Cu compounds after mechanical treatment

We have investigated the influence of mechanical alloying on structural changes and magnetic properties of the SmNi4Cu compound. This compound crystallizes in the hexagonal structure of CaCu5, space group P6/mmm. SmNi4Cu is ferromagnetic with the Curie temperature of 34 K and the saturation magnetic moment of 0.36 µB at 4.2 K. The decrease of intensity and broadening of the diffraction lines have been detected after milling as a consequence of the grains' size reduction. The analysis of the as-prepared sample using EDAX has revealed a stable composition without a presence of any additional phases and elements. The obtained results show that the magnetic properties significantly depend on the milling time. The temperature and magnetic field dependences of the magnetization exhibit a presence of antiferromagnetic-like behavior of the milled samples. The transition temperature does not vary as a function of the milling time. (© 2006 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)