Journal <strong>of</strong> <strong>the</strong> American Chemical Society Article field transition. The nearly identical value for 10Dq from absorption and <strong>the</strong> simul<strong>at</strong>ed XANES d<strong>at</strong>a indic<strong>at</strong>es <strong>the</strong> <strong>Cr</strong>(III) ion is tetragonally distorted due to pair form<strong>at</strong>ion <strong>of</strong> <strong>Cr</strong> octahedral by removal <strong>of</strong> three Zn ions for each pair <strong>of</strong> <strong>Cr</strong> ions in <strong>the</strong> l<strong>at</strong>tice. The sharing <strong>of</strong> <strong>the</strong> O h edge by <strong>the</strong> <strong>Cr</strong>(III) ions in <strong>the</strong> ZnSe l<strong>at</strong>tice produces a minimally distorted site in <strong>the</strong> l<strong>at</strong>tice analogous to spinel inclusions in bulk metal chalcogenide structures. The ZFC/FC susceptibility measurement shows PM behavior with AFM exchange coupling <strong>at</strong> low temper<strong>at</strong>ure. The calcul<strong>at</strong>ed <strong>Cr</strong>(III)−<strong>Cr</strong>(III) J NN value (Z = 4) for <strong>the</strong> QD (−12.5 K) is consistent with reported bulk values and supports a model <strong>of</strong> Zn<strong>Cr</strong> 2 Se 4 spinel inclusion within <strong>the</strong> core <strong>of</strong> <strong>the</strong> QD. High-frequency EPR d<strong>at</strong>a are quite consistent with <strong>Cr</strong> (III) in an O h environment, exhibiting only <strong>the</strong> Zeeman interaction and no o<strong>the</strong>r splitting. Fur<strong>the</strong>r studies are underway to analyze <strong>the</strong> <strong>Cr</strong>−<strong>Cr</strong> nearest-neighbor distances via EXAFS and <strong>the</strong> exchange coupling <strong>of</strong> <strong>the</strong> inclusion to <strong>the</strong> band structure <strong>of</strong> <strong>the</strong> ZnSe l<strong>at</strong>tice using XMCD and magneto-optical methods. The intriguing ability to incorpor<strong>at</strong>e a magnetic inclusion in an o<strong>the</strong>rwise crystalline QD opens a new class <strong>of</strong> dilute magnetic semiconductor QDs for fur<strong>the</strong>r studies. ■ ASSOCIATED CONTENT *S Supporting Inform<strong>at</strong>ion TEM images and size disperisty analysis, UV−vis and <strong>Cr</strong>(III) concentr<strong>at</strong>ion-dependent PL quantum yield, XRF elemental composition, pXRD comparisons to standards, crystal field spectra fit <strong>of</strong> <strong>the</strong> 4 A 2g → 4 T 2g transition, <strong>the</strong>oretical splitting behavior for <strong>Cr</strong>(III) EPR, Zn and Se L 3 edge XANES d<strong>at</strong>a, and EPR and XRF d<strong>at</strong>a after chemical etching <strong>of</strong> 2.5% Zn 1−x <strong>Cr</strong> x Se QDs. This m<strong>at</strong>erial is available free <strong>of</strong> charge via <strong>the</strong> Internet <strong>at</strong> http://pubs.acs.org. ■ AUTHOR INFORMATION Corresponding Author strouse@chem.fsu.edu Notes The authors declare no competing financial interest. ■ ACKNOWLEDGMENTS We wish to thank NSF-CHE-0911080 and NSF-DMR-0701462 for financial support and <strong>the</strong> N<strong>at</strong>ional High Magnetic Field Labor<strong>at</strong>ory via <strong>the</strong> NSF Cooper<strong>at</strong>ive Agreement no. DMR- 0654118 and <strong>the</strong> St<strong>at</strong>e <strong>of</strong> Florida. XANES research described in this paper was performed <strong>at</strong> <strong>the</strong> Canadian Light Source, which is supported by <strong>the</strong> N<strong>at</strong>ural Sciences and Engineering Research Council <strong>of</strong> Canada, <strong>the</strong> N<strong>at</strong>ional Research Council Canada, <strong>the</strong> Canadian Institutes <strong>of</strong> Health Research, <strong>the</strong> Province <strong>of</strong> Sask<strong>at</strong>chewan, Western Economic Diversific<strong>at</strong>ion Canada, and <strong>the</strong> University <strong>of</strong> Sask<strong>at</strong>chewan. K.S. is thankful to Department <strong>of</strong> Science and Technology, Government <strong>of</strong> India for providing financial assistance to carry out advanced research work <strong>at</strong> FSU in <strong>the</strong> United St<strong>at</strong>es under <strong>the</strong> BOYSCAST scheme. 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