摘要
SnO_(2) nanopowders were pressed into pellets and annealed in air from 100 to 1400℃.Both XRD and Raman spectroscopy confirm that all annealed samples were single phase with a tetragonal rutile structure.Annealing induces an increase in the SnO_(2) grain size from 30 to 83 nm.Positron annihilation measurements reveal vacancy defects in the grain boundary region,and the interfacial defects remain stable after annealing below 400℃,then they are gradually recovered with increasing annealing temperature up to 1200℃.Room temperature ferromagnetism was observed for SnO_(2) nanocrystals annealed below 1200℃,and the magnetization decreases continuously with increasing annealing temperature.However,the ferromagnetism disappears at 1200℃ annealing.This shows good coincidence with the recovery of interfacial defects in the nanocrystals,suggesting that the ferromagnetism is probably induced by vacancy defects in the interface region.
作者
CHEN Zhi-Yuan
CHEN Zhi-Quan
PAN Rui-Kun
WANG Shao-Jie
陈志远;陈志权;潘瑞琨;王少阶(School of Nuclear Technology and Chemistry and Biology,Hubei University of Science and Technology,Xianning 437100;Hubei Nuclear Solid Physics Key Laboratory,Department of Physics,Wuhan University,Wuhan 430072;School of Materials Science and Engineering,Hubei University,Wuhan 430062)
基金
Supported by the National Natural Science Foundation of China under Grant Nos 11075120, 10974149 and 51272072
the Natural Science Foundation of Hubei Province under Grant No 2011CDC060
the Program for Excellent youth Talents of Hubei Province Education Department under Grant No Q20122803.
