The influence of solvents on the microstructure and magnetic properties of Co2FeAl Heusler alloy nanoparticles

The Co2FeAl alloy nanoparticles were prepared by using different solvents (MeOH, MEG, ET and deionized water) from solutions. X-ray diffraction analysis and magnetic investigation confirmed good reduction ability of MeOH. By using MeOH as solvent, pure crystalline structures had been got in Co2FeAl alloy nanoparticles when the annealing temperature was larger than 400 degrees C. With the increasing of annealing temperature, the saturation magnetization (100.8 emu/g) and coercivity (332.4 Oe) of Co2FeAl alloy nanoparticles increased and decreased gradually. When annealing at 500 degrees C, the grain size ranged from 50 to 100 nm with M-s = 128.5 emu/g and H-c = 179.8 Oe. With further increasing annealing temperature to 800 degrees C, the maximum saturation magnetization (185.6 emu/g) and the minimum coercivity (88.2 Oe) were obtained which indicated the best Co2FeAl alloy nanoparticles.