Date of this Version
Reductive chemical synthesis is a versatile tool for fabricating elemental nanostructures; however, less work has been completed on understanding and controlling alloy formation. Magnetic Mg–Co and Mg–Co–C nanocomposites have been fabricated using a reductive chemical synthesis designed to produce highly active metals. The as-synthesized powder was annealed at temperatures from 150 to 650 °C. Samples were investigated using x-ray diffraction, alternating gradient force magnetometry, and superconducting quantum interference device magnetometry. X-ray diffraction indicates that the resulting structures are multiphase with MgCo2, MgCo3C0. 5, fcc Co, Mg, MgO, and Li2CO3 present depending on annealing temperature. The temperature-dependent magnetization of the as-synthesized sample indicates ferromagnetic and antiferromagnetic or ferrimagnetic contributions. Increases in coercivity and remanance ratio with increasing annealing temperature are consistent with the formation and growth of small Co grains.