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Byline: K.L. Teo, T.C. Chong In this work, we give a review on the nanoscale cubic-islands growth of SrS and ZnxSr1-xS [abbreviated as (ZnSr)S] thin films by solid-source molecular-beam epitaxy (MBE). Our detailed analyses of scanning electron microscopy (SEM) and atomic force microscopy (AFM) images show that different sizes of SrS islands can be achieved depending on the substrate temperature. Reflection high-energy electron diffraction (RHEED) and X-ray diffraction (XRD) establish cube-on-cube (001)SrS ' (001)MgO with [001]SrS ' [001]MgO epitaxial relationship. All these results point towards the growth to occur in step-flow mode. When (ZnSr)S is codoped with europium and samarium ions (SrS : Eu, Sm and ZnSrS : Eu, Sm), infrared-stimulated luminescence (ISL) with a peak at 612 nm is observed at room temperature, which is stimulated with infrared light after irradiation with visible light. The ISL results show that the (ZnSr)S system can be developed for erasable and rewritable optical memory.

The growth and magnetic properties of BeTe with Cr doping grown on GaAs(001) substrate at Te-rich condition by solid-source molecular-beam epitaxy is presented. Results show that the ferromagnetic ordering of Be(Cr)Te films could be attributed to precipitations of NiAs C[r.sub.1-[delta]]Te.

A ballistic device model which harnesses the Dresselhaus spin-orbit coupling effect to induce spin polarization [P] is proposed. Calculations for GaAs, GaSb, and InSb show a field enhancement of [P] from peak 2%-3% to 10%-80% near the conduction band.

A device model is produced that couples spin to the crystal field, external magnetic, and transverse electric field E(sub y), such that current j(sub x) transport in the ballistic regime. As E(sub y) modulates j(sub x) and its polarization P at a particular distance y, the model shows that the Landau spin-orbit system could implement the functions of a spin-field effect transistor.

A drift-diffusion transport model to evaluate the spin-injection efficiency eta and magnetoresistance (MR) ratio in a ferromagnetic (FM) metal-semiconductor (SC)-FM metal trilayer structure is presented. The presence of interfacial resistances (IR) at the FM-SC boundary is found to be crucial for generating a large spin splitting of mu, and consequently a high injection efficiency eta.

The hydrostatic pressure dependence of Ge nanocrystals embedded into SiO2 matrix on the quartz-glass substrate by Raman scattering at room temperature is studied. A simple elastic model, which describes the effective pressure transmitted from matrix to the nanocrystals, is used to explain the results.

In this paper, the enclosing control problem of second-order multi-agent systems is considered, where the targets can be either stationary or moving. The objective is to achieve an equidistant circular formation for a group of agents to enclose a team of targets. In order to do so, we first introduce a formal definition explaining certain basic properties of the exploring relation between the agents and the targets. We then construct the estimator of the centre of the targets, which is used to build the control protocol to achieve equidistant circular enclosing. Using a Lyapunov function and Lasalle’s Invariance Principle, the convergency of the estimator and control protocol are, respectively, established. We then construct a smooth function to approximate the discontinuous term in the estimator. Finally, the simulations for stationary targets and moving targets are given to verify the validity of the results obtained. [ABSTRACT FROM AUTHOR]