Mild Hydrothermal Synthesis of Ni–Cu Nanoparticles

Magnetic Ni-rich Ni–Cu nanoparticles with Ni : Cu mass ratio (S) of 2.0 and 2.6 were prepared using a mixture of polyoxyethylene (10) isooctylphenyl ether (Triton X-100) and sodium dodecyl sulfate (SDS) in a mild hydrothermal condition at 95ºC. X-ray diffractometry (XRD) showed that the nanoparticles prepared at S=2.0 possessed Ni–Cu alloy characteristic whereas the characteristic was absent at S=2.6. The XRD data was enhanced by Fourier transform infrared spectroscopy (FTIR) which exhibited metal-metal (Ni–Cu) band at 455 cm−1. Based on transmission electron microscopy (TEM), the average particle sizes for the nanoparticles prepared at S=2.0 and 2.6 were in the range of 19–23 nm. The as-prepared nanoparticles exhibited paramagnetic behaviour measured using a vibrating sample magnetometer (VSM) and the specific saturation magnetization decreased at the higher concentration of Ni