Anomalous ferromagnetic behavior of CuO nanorods synthesized via hydrothermal method

Copper monoxide (CuO) nanorods of 30–40 nm in diameter and 100–200 nm in length were successfully synthesized using a hydrothermal reaction method in the presence of sodium citrate. On the basis of the morphology observation and X-ray diffraction patterns of the samples, a possible growth mechanism of the CuO nanorods was proposed. The magnetic properties of CuO nanorods were studied using a SQUID magnetometer and a vibrating sample magnetometer. It was interesting to note that the as-synthesized CuO nanorods showed an anomalous ferromagnetic behavior. The coercive force ( H c ) for the CuO nanorods at T = 5 K and T = 300 K were estimated to be 331.39 and 175.88 Oe, respectively. The anomalous ferromagnetic behavior of the as-synthesized CuO nanorods was discussed in terms of the effect of the peculiar morphology.