Effect of size on momentum distribution of electrons around vacancies in NiO nanoparticles  

作　　者：Anjan Das Atis Chandra Mandal P.M.G.Nambissan 

机构地区：[1]Department of Physics, A.P.C.Roy Government College [2]Department of Physics, University of Burdwan [3]Applied Nuclear Physics Division,Saha Institute of Nuclear Physics

出　　处：《Chinese Physics B》2015年第4期296-299,共4页中国物理B（英文版）

摘　　要：Very small nickel oxide nanoparticles were prepared by a sol-gel procedure using nickel nitrate hexahydrate and ammonium hydroxide as precursors. The particles are in the range of 5 nm-11 rim. The x-ray diffraction （XRD） crystallography and high resolution transmission electron microscopy （HRTEM） were employed to characterize the samples. They were found to be polycrystalline in nature and fcc （NaCl-type） in structure, with the lattice parameter varying with annealing temperature. HRTEM pictures show that the as-prepared samples are hexagonal in shape. Positron annihilation spectroscopy was used to investigate the Doppler-broadened spectra of the samples. The S and W parameters revealed that the chemical surroundings and momentum distribution of the vacancy clusters vary with crystallite size.Very small nickel oxide nanoparticles were prepared by a sol-gel procedure using nickel nitrate hexahydrate and ammonium hydroxide as precursors. The particles are in the range of 5 nm-11 rim. The x-ray diffraction （XRD） crystallography and high resolution transmission electron microscopy （HRTEM） were employed to characterize the samples. They were found to be polycrystalline in nature and fcc （NaCl-type） in structure, with the lattice parameter varying with annealing temperature. HRTEM pictures show that the as-prepared samples are hexagonal in shape. Positron annihilation spectroscopy was used to investigate the Doppler-broadened spectra of the samples. The S and W parameters revealed that the chemical surroundings and momentum distribution of the vacancy clusters vary with crystallite size.

关 键 词：nanoparticles SEMICONDUCTOR defect cluster positron annihilation SOL-GEL 

分 类 号：O614.813[理学—无机化学] TB383.1[理学—化学]