Open Access Nano Express

Vacancy-Mediated Magnetism in Pure Copper Oxide Nanoparticles

Daqiang Gao, Jing Zhang, Jingyi Zhu, Jing Qi, Zhaohui Zhang, Wenbo Sui, Huigang Shi and Desheng Xue*

Author Affiliations

Key Laboratory for Magnetism and Magnetic Materials of MOE, Lanzhou University, 730000, Lanzhou, People’s Republic of China

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Nanoscale Research Letters 2010, 5:769-772  doi:10.1007/s11671-010-9555-8

Published: 16 February 2010

Abstract

Room temperature ferromagnetism (RTF) is observed in pure copper oxide (CuO) nanoparticles which were prepared by precipitation method with the post-annealing in air without any ferromagnetic dopant. X-ray photoelectron spectroscopy (XPS) result indicates that the mixture valence states of Cu1+ and Cu2+ ions exist at the surface of the particles. Vacuum annealing enhances the ferromagnetism (FM) of CuO nanoparticles, while oxygen atmosphere annealing reduces it. The origin of FM is suggested to the oxygen vacancies at the surface/or interface of the particles. Such a ferromagnet without the presence of any transition metal could be a very good option for a class of spintronics.

Keywords:
CuO; Nanoparticles; X-ray photoelectron spectroscopy; Room temperature ferromagnetism