title: Exposure of the hidden anti-ferromagnetism in paramagnetic CdSe:Mn nanocrystals.
abstract: We present theoretical and experimental investigations of the magnetism of paramagnetic semiconductor CdSe:Mn nanocrystals and propose an efficient approach to the exposure and analysis of the underlying anti-ferromagnetic interactions between magnetic ions therein. A key advance made here is the development of an analysis method with the exploitation of group theory technique that allows us to distinguish the anti-ferromagnetic interactions between aggregative Mn(2+) ions from the overall pronounced paramagnetism of magnetic-ion-doped semiconductor nanocrystals. By using the method, we clearly reveal and identify the signatures of anti-ferromagnetism from the measured temperature-dependent magnetisms and furthermore determine the average number of Mn(2+) ions and the fraction of aggregative ones in the measured CdSe:Mn nanocrystals.
authors.affiliation: Department of Electrophysics, National Chiao Tung University , Hsinchu 300, Taiwan.
authors.forename: Shou-Jyun
authors.initials: SJ
authors.lastname: Zou
authors.forename: Sheng-Tsung
authors.initials: ST
authors.lastname: Wang
authors.forename: Ming-Fan
authors.initials: MF
authors.lastname: Wu
authors.forename: Wen-Bin
authors.initials: WB
authors.lastname: Jian
authors.forename: Shun-Jen
authors.initials: SJ
authors.lastname: Cheng
keywords: CdSe; Mn; anti-ferromagnetism; magnetic semiconductor nanocrystals; paramagnetism