Duc Anh Le

Epitaxial growth and properties of n-type magnetic semiconductor (In,Co)As

A new n-type magnetic semiconductor (In1-xCox)As has been successfully grown by low-temperature molecular beam epitaxy (LT-MBE) on GaAs (001) substrates. Reflection high energy electron diffraction (RHEED) patterns indicate that (In,Co)As layers with the Co concentration x = 3 21% remain zinc-blende crystal structure. The electron concentration can be controlled between 2.4×10 18 4.9×10 19 cm -3 by changing the Co concentration. The insulator-metal transition is observed at x = 5%. Large negative magnetoresistance (up to 17.5% at 9.5kG) is observed at 5K and can be attributed to spin-disorder scattering.