Evidence for ligand-induced paramagnetism in CdSe quantum dots.
We report evidence that paramagnetism in CdSe QDs can be induced via manipulation of the surface chemistry. Using SQUID magnetometry and X-ray absorption spectroscopy, we demonstrate that the paramagnetic behavior of the CdSe QDs can be varied by changing the ligand end-group functionality of the passivating layer. Contrary to previous reports, no evidence for ferromagnetism was observed. The results suggest that the paramagnetism is induced via pi back-bonding between Cd 4d orbtials and ligands with empty pi* orbitals.
Meulenberg
Robert W
RW
Lawrence Livermore National Laboratory, Livermore, California 94550, USA. robert.meulenberg@maine.edu
Lee
Jonathan R I
JR
McCall
Scott K
SK
Hanif
Khalid M
KM
Haskel
Daniel
D
Lang
Jonathan C
JC
Terminello
Louis J
LJ
van Buuren
Tony
T