MICROSTRUCTURE AND PREPARATION OF Ni,Al AND Fe NANOPOWDERS
(1.Department of Applied Physics and Heat Engineering; Central South University of Technology; Changsha 410083;
2.International Centre for Materials Physics; Chinese Aca)
2.International Centre for Materials Physics; Chinese Aca)
Abstract: By means of mechanical physical solid state reaction methods (MPSSRM), 5～25 nm powders of iron, nickel, aluminium have been prepared. The powders exhibit few clusters of monocrystal and polycrystal, the eletronic structure of which were identified by X ray diffraction and XPS. The experiments show that there is an oxide layer on the surfaces of Ni, Al, Fe nanopowders. DTA experiments show that the peak point temperature of primal temperature decreases with the decrease of the particle diameter, and tends to move in low temperature direction on the DTA curve of Fe nanopowder. The relationship between the particle diameter ( d ) of Fe nanopowder and surface energy (Δ H ) can be given by Δ H ∝ d -1/2 .
Key words: nanopowder microstructure electronic structure surface energy