Exposure of the hidden anti-ferromagnetism in paramagnetic CdSe:Mn nanocrystals.

Zou, Shou-Jyun; Wang, Sheng-Tsung; Wu, Ming-Fan; Jian, Wen-Bin; Cheng, Shun-Jen · ACS Nano · 2015

basic_science · Level V

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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.