Spintronics

AbstractRecent successes by a Nottingham University group includes the growth of GaMnAs material with world record Curie temperatures, and ferromagnetic TiCoO2 and GaMnN which shows ferromagnetism at room temperature. A characteristic of the GaMnAs layers grown by the group is their low resistivity that is accompanied by very weak high field magneto-resistance. This has enabled the group to separate the normal and anomalous contributions to the Hall effect and make the first accurate measurements of hole densities across a range of Mn compositions. Using this information the first meaningful comparison of theoretically predicted Curie temperatures and extraordinary Hall conductivities with experiment have been made. The samples were grown by Low Temperature Molecular Beam Epitaxy (LTMBE) technique. The In composition of InGaAs superlattice spacers and InGaMnAs magnetic layers was chosen to be equal to 50% while the Mn concentration was equal to 5.5% in GaMnAs single layers and 6% in the magnetic layers of superlattice structures.Visit www.three-fives.com for the latest advanced semiconductor industry new