By Topic

Evidence of Oxygen Vacancies Enhancing the Room Temperature Ferromagnetism in CeO _{2{-}{\rm x}} Nanopowders

Sign In

Cookies must be enabled to login.After enabling cookies , please use refresh or reload or ctrl+f5 on the browser for the login options.

Formats Non-Member Member
$33 $13
Learn how you can qualify for the best price for this item!
Become an IEEE Member or Subscribe to
IEEE Xplore for exclusive pricing!
close button

puzzle piece

IEEE membership options for an individual and IEEE Xplore subscriptions for an organization offer the most affordable access to essential journal articles, conference papers, standards, eBooks, and eLearning courses.

Learn more about:

IEEE membership

IEEE Xplore subscriptions

6 Author(s)
Mingjie Li ; Key Lab. for Magn. & Magn. Mater. of Minist. of Educ., Lanzhou Univ., Lanzhou ; Shihui Ge ; Yalu Zuo ; Li Zhang
more authors

To investigate whether oxygen vacancies play an important role in the origin of ferromagnetism in undoped nanosized metal oxides, CeO2-x nanopowders were prepared using sol-gel method, and anneal studies under various atmosphere were carried out on samples. The room temperature ferromagnetism in the samples was enhanced after being hydrogenated at 320degC in a forming gas (Ar90%+H210%) and weakened after reheating the sample in air. These variations of the magnetization have been observed for additional cycles by alternately heating in air and Ar/H2. Raman spectroscopy study reveals that hydrogenation leads an increase in the amount of oxygen vacancies in these H2 -annealed samples. It is demonstrated that this observed ferromagnetism is intrinsic and affected by the oxygen vacancies which are produced by hydrogenation but reduced by oxidation. A correlation of ferromagnetism with concentration of oxygen vacancies is obtained in CeO2-x nanopowders.

Published in:

IEEE Transactions on Magnetics  (Volume:44 ,  Issue: 11 )