LATTICE EXPANSION IN NANOCRYSTALLINE PURE Ni
纯镍纳米晶体的晶格膨胀

The lattice structure of nanocrystalline pure Ni. prepared by high-frequency sputtering, has been investigated. The lattice parameter of nanocrystalline Ni samples with grain sizes ranging from 6 to 15 nm was measured accurately by X-ray diffraction. It was found that the lattice parameter(a) for the nanocrystallie samples is larger than that for the perfect Ni single crystal(ao), and the value of a increases significantly with the decrease of grain size. According to the thermodynamic theory, the lattice expansion in the nanocrystalline sample was explained.