Direct Observation of sp-d exchange interactions in colloidal Mn2+- and Co2+-doped CdSe quantum dots.

Autor: Archer PI; Department of Chemistry, University of Washington, Seattle, Washington 98195-1700, USA., Santangelo SA, Gamelin DR
Jazyk: angličtina
Zdroj: Nano letters [Nano Lett] 2007 Apr; Vol. 7 (4), pp. 1037-43. Date of Electronic Publication: 2007 Mar 23.
DOI: 10.1021/nl0702362
Abstrakt: The defining attribute of a diluted magnetic semiconductor (DMS) is the existence of dopant-carrier magnetic exchange interactions. In this letter, we report the first direct observation of such exchange interactions in colloidal doped CdSe nanocrystals. Doped CdSe quantum dots were synthesized by thermal decomposition of (Me4N)2[Cd4(SePh)10] in the presence of TMCl2 (TM2+ = Mn2+ or Co2+) in hexadecylamine and were characterized by several analytical and spectroscopic techniques. Using magnetic circular dichroism spectroscopy, successful doping and the existence of giant excitonic Zeeman splittings in both Mn2+- and Co2+-doped wurtzite CdSe quantum dots are demonstrated unambiguously.
Databáze: MEDLINE