DEFECT OF NANOCRYSTALLINE COPPER AND SILVER

Nanoscale copper and silver were synthesized by the H-2 + Ar are plasm a method. During the synthesis, hydrogen molecules were dissociated in to hydrogen atoms and stored in the particles. At the same rime, nanom eter copper and silver particles were prepared by the inert gas conden sation method whose power is about identical with the hydrogen are pla sma method. Various specimens were annealed respectively at low temper ature. The particle size was measured by a transmission electron micro scopy. A proper temperature was chosen to prepare the standard specime n. The defects of nano-copper and nano-silver were studied by TEM, HRT EM, XRD profile refinement and Fourier analysis method. The asymmetry of XRD profile of both specimens was discovered and the significance o f the asymmetry was studied. The probability of twin existing in the n ano-materials was calculated using Fourier analysis method, and the ef fect of hydrogen on the structure was discussed.