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We report on the structural, electrical and magnetic properties of ZnCoO thin films grown by atomic layer deposition method using reactive organic precursors of zinc and cobalt. As a zinc precursor we applied either dimethylzinc or diethylzinc and cobalt(II) acetyloacetonate as a cobalt precursor. The use of these precursors allowed us the significant reduction of a growth temperature to 300 °C and below, which proved to be very important for the growth of uniform films of ZnCoO. Structural, electrical and magnetic properties of the obtained ZnCoO layers will be discussed based on the results of secondary ion mass spectroscopy, scanning electron microscopy, energy dispersive spectroscopy, X-ray diffraction, atomic force microscopy, Hall effect and SQUID investigations. [ABSTRACT FROM AUTHOR]

Abstract: In x Ga1−x As layers on InP substrate can be subjected to compressive or tensile strain due to lattice parameter differences depending on the alloy composition. In order to examine in details the strain of InGaAs/InP epiatxial layers and its evolution after subjecting the layers to annealing at high pressure, X-ray synchrotron topography, high resolution X-ray diffraction and atomic force microscopy have been employed. The data show that the changes of structural properties of the InGaAs layers subjected to high temperature–high pressure treatment at 670K–1.2Gpa, strongly depend on initial strain state and defect structure. The annealing of samples under high pressure results in change of strain in tensile layers only. The behaviour of observed defects is discussed. [Copyright &y& Elsevier]

Cr-based diluted magnetic semiconductors (DMSs) have attracted a lot of attention within the last few years because of their possible applications in the area of spintronics. Modern growth techniques of such materials require efficient methods of characterization of their structure. In this work, the structure of Cr-rich ZnSe layers grown by MBE on (0 0 1) GaAs substrate was investigated by means of the high-resolution X-ray diffraction, atomic force microscopy and Raman scattering. Direct evidence of the mixed Zn1-xCrxSe crystal in the zinc-blende phase is demonstrated by the high resolution X-ray diffraction (a part of Cr is shown to occupy the cationic sites in the crystal lattice). The presence of amorphous or crystalline Se- and Cr-related precipitates in selected samples is demonstrated, their influence on the properties of (Zn,Cr)Se layers is discussed. [Copyright &y& Elsevier]

Recently, ZnO attracts a wide interest as a promising material for the application in optoelectronic devices working in the blue and ultraviolet region and (when doped with magnetic impurities) in spintronic devices. Unfortunately, the technology of good, large (e.g.: 2.5–5 cm in diameter) single crystals is very difficult, even as compared with other II–VI compounds. We report on the successful growth of the ZnO crystals with a chemical vapour transport (CVT) method and on the characterisation of them. The source material is synthesised at 650 °C from oxygen and zinc vapours and subsequently, baked (as a powder) to achieve stoichiometry. The crystals grow (with the rate 1–2 mm per day) in the graphite-covered quartz ampoules containing pure (6N) hydrogen or nitrogen and a small amount of water vapour. The crystals, both as-grown and annealed in pure oxygen, are characterised by the measurements of photoluminescence spectra, transmission spectra, far infrared transmission, X-ray diffraction and electrical transport. The surface region is analysed by the secondary ion mass spectroscopy (SIMS). [Copyright &y& Elsevier]

Abstract: GaMnAs layers on (001)-oriented GaAs substrates were grown by the molecular beam epitaxy (MBE) method. Structural properties of samples processed at up to 920K under hydrostatic Ar pressure up to 1.1GPa were investigated by X-ray, secondary ion mass spectroscopy and atomic force microscopy methods. The sign of strain (compressive or tensile) of the GaMnAs layers, related to a creation of MnAs nanoclusters, is found to be dependent on processing conditions and on primary structure defects, whereas it was independent of Mn concentration. An influence of the defects structure in as-grown samples on the strain state of processed GaMnAs layers is discussed. [Copyright &y& Elsevier]