Title :
Structure and spin-glass properties of Cd0.5Mn0.5 S diluted magnetic semiconductor quantum dots
Author :
Bandaranayake, R.J. ; Lin, J.Y. ; Jiang, H.X. ; Sorensen, C.M.
Author_Institution :
Dept. of Phys., Kansas State Univ., Manhattan, KS, USA
fDate :
11/1/1995 12:00:00 AM
Abstract :
Cd0.5Mn0.5S diluted magnetic semiconductor (DMS) quantum dots (QDs) of crystallite size ranging from 24 Å to the bulk have been chemically synthesized using an aqueous solution precipitation method and thermal annealing. Subsequent characterization indicates that the “as prepared” material is of the cubic zinc blende structure which evolves with increasing size to the bulk hexagonal wurtzite structure. Magnetic properties of the DMS QDs have been measured with a SQUID magnetometer. A transition from a paramagnetic to a spin-glass (SG) state at a critical temperature Tf has been observed. Size dependence measurements on Tf indicate a minimum size for SG formation. Relaxation in isothermal remanent magnetization has also been measured and shows a power law decay
Keywords :
cadmium compounds; magnetic transition temperature; manganese compounds; remanence; semiconductor quantum dots; semimagnetic semiconductors; spin glasses; Cd0.5Mn0.5S; SQUID magnetometer; aqueous solution precipitation; chemical synthesis; critical temperature; cubic zinc blende structure; diluted magnetic semiconductor; hexagonal wurtzite structure; isothermal remanent magnetization; magnetic properties; paramagnetic transition; quantum dots; relaxation; spin glass; thermal annealing; Annealing; Chemicals; Crystalline materials; Crystallization; Magnetic materials; Magnetic semiconductors; Paramagnetic materials; Quantum dots; Semiconductor materials; Zinc;
Journal_Title :
Magnetics, IEEE Transactions on
