TY - JOUR
T1 - High-field electron paramagnetic resonance as a microscopic probe of anisotropic strain at Mn 2+ sites in CdSe:Mn 2+ quantum dots
AU - Wang, Zhenxing
AU - Zheng, Weiwei
AU - Van Tol, Johan
AU - Dalal, Naresh S.
AU - Strouse, Geoffrey F.
PY - 2012/2/6
Y1 - 2012/2/6
N2 - High-frequency electron paramagnetic resonance (HF-EPR) provides a contactless microscopic probe of magnetic impurities and their surroundings in nanoparticles. In 5.0 nm colloidally prepared CdSe quantum dots (QDs) containing 0.6% Mn 2+, a core and a surface site can be readily distinguished on the basis of g-factor and 55Mn hyperfine interaction. In contrast to EPR in the bulk, at low temperatures a broad background signal develops, which at high fields is the only remaining feature. Previous studies have suggested this background signal originates from exchange coupled Mn 2+ clusters arising from spinodal decomposition; HF-EPR shows that it is due to strain-broadening of the zero-field splitting related to local lattice distortions within the QD.
AB - High-frequency electron paramagnetic resonance (HF-EPR) provides a contactless microscopic probe of magnetic impurities and their surroundings in nanoparticles. In 5.0 nm colloidally prepared CdSe quantum dots (QDs) containing 0.6% Mn 2+, a core and a surface site can be readily distinguished on the basis of g-factor and 55Mn hyperfine interaction. In contrast to EPR in the bulk, at low temperatures a broad background signal develops, which at high fields is the only remaining feature. Previous studies have suggested this background signal originates from exchange coupled Mn 2+ clusters arising from spinodal decomposition; HF-EPR shows that it is due to strain-broadening of the zero-field splitting related to local lattice distortions within the QD.
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U2 - 10.1016/j.cplett.2011.12.038
DO - 10.1016/j.cplett.2011.12.038
M3 - Article
AN - SCOPUS:84862777071
VL - 524
SP - 73
EP - 77
JO - Chemical Physics Letters
JF - Chemical Physics Letters
SN - 0009-2614
ER -