Magnetic Behavior of Manganese-Doped ZnSe Quantum Dots

Authors

Amit D. Lad, University of Pune
Ch. Rajesh, University of Pune
Mahmud Khan, Southern Illinois University Carbondale
Naushad Ali, Southern Illinois University Carbondale
I. K. Gopalakrishnan, Bhabha Atomic Research Centre
S. K. Kulshreshtha, Bhabha Atomic Research Centre
Shailaja Mahamuni, University of Pune

Comments

© 2007 American Institute of Physics

Published in Journal of Applied Physics, Vol. 101 No. 10 (2007) at doi: 10.1063/1.2733625

Abstract

Magnetic properties of manganese-doped ZnSe quantum dots with the size of approximately 3.6 nm are investigated. The amount of Mn in the ZnSe quantum dots has been varied from 0.10% to 1.33%. The doping level in the quantum dots is much less than that used in the precursor. The co-ordination of Mn in the ZnSe lattice has been determined by electron paramagnetic resonance (EPR). Two different hyperfine couplings 67.3×10⁻⁴ and 60.9×10⁻⁴ cm⁻¹ observed in the EPR spectrum imply that Mn atoms occupy two distinct sites; one uncoordinated (near the surface) and other having a cubic symmetric environment (nanocrystal core), respectively. Photoluminescence measurements also confirm the incorporation of Mn in ZnSe quantum dots. From the Curie-Weiss behavior of the susceptibility, the effective Mn-Mn antiferromagnetic exchange constant (J₁) has been evaluated. The spin-glass behavior is observed in 1.33% Mn-doped ZnSe quantum dots, at low temperature. Magnetic behavior at a low temperature is discussed.

Recommended Citation

Lad, Amit D., Rajesh, Ch., Khan, Mahmud, Ali, Naushad, Gopalakrishnan, I. K., Kulshreshtha, S. K. and Mahamuni, Shailaja. "Magnetic Behavior of Manganese-Doped ZnSe Quantum Dots." (May 2007).