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A set of GaN/GaInN single quantum wells (SQWs) were grown on c-plane GaN/sapphire templates using metal organic vapor phase epitaxy (MOVPE) and atomic layer epitaxy (ALE). The structural information on the interfaces and surfaces was obtained by fitting the experimental X-ray spectra and was compared between MOVPE and ALE mode. The X-ray crystal truncation rod (CTR) scattering measurement results showed that the samples grown by ALE had sharper interfaces than those grown by MOVPE. Both the X-ray reflectivity (XRR) curve-fitting results and atomic force microscope (AFM) results indicated that the surfaces of the ALE-grown SQWs were smoother than those of MOVPE-grown SQWs. (© 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [ABSTRACT FROM AUTHOR]

Abstract: GaN/In x Ga1−x N/GaN single quantum wells (SQWs) have been grown on c-plane GaN/sapphire substrates using MOVPE system. PL (photoluminescence) and AFM (atomic force microscope) measurements demonstrate good quality of after-growth thermal-annealed SQWs. In situ XRD (X-ray diffraction), XRR (X-ray reflectivity), and X-ray CTR (crystal truncation rod) scattering measurements were successfully conducted on the SQWs under the NH3+N2 ambient at 1103K. The analysis results of the XRR and the X-ray CTR spectra at 1103K and at 300K on the same sample matched well. It demonstrated that In0.09Ga0.91N SQW structure with several ML (monolayer) InGaN thicknesses was successfully investigated using the XRR and CTR scattering measurements at 1103K. [Copyright &y& Elsevier]

Abstract: The growth of In x Ga1−x N layers on c-plane GaN (2μm)/sapphire (0001) substrates was carried out using the special growth system installed in an X-ray diffractometer using solely N2 as the carrier gas. X-ray CTR scatterings on In x Ga1−x N layer were measured at growth temperatures and after cooling down to room temperature. The differences in X-ray CTR scattering spectra at growth temperatures and at room temperature were discussed. The peak InN (0002) or InGaN was observed at growth temperature. On the other hand, In (101) and In (002) peaks were observed with InN (002) or In x Ga1−x N in the X-ray CTR spectra after cooling down to room temperature. These differences should be important to reveal the real growth processes of In x Ga1−x N. Single diffraction peaks of In0.16Ga0.84N and In0.38Ga0.62N films were observed at 830 and 780°C, respectively. [Copyright &y& Elsevier]

Abstract: We have grown ErP on Ga0.52In0.48P (001) lattice-matched to GaAs and on InP (001) by low-pressure organometallic vapor phase epitaxy and investigated the surface morphology of ErP layers. Lattice-mismatch in ErP/Ga0.52In0.48P/GaAs heterostructures (Δa / a =−0.8%) is much less than that of ErP/InP heterostructures (−4.5%). Extended X-ray absorption fine structure measurement revealed that Er exists in the form of ErP rock-salt structure in both samples. The estimated growth rate of ErP on Ga0.52In0.48P is 1.8 ML/h. Our results demonstrate that ErP on Ga0.52In0.48P has smaller surface roughness than ErP on InP. Moreover, an ErP layer exists underneath the surface about 2 ML and the surface roughness does not depend on the ErP thickness in the range of our experiments (2.2–13.7 ML). [Copyright &y& Elsevier]

In the present paper we discuss correlations between crystal structure and magnetic properties of epitaxial ε-Fe 2 O 3 films grown on GaN. The large magnetocrystalline anisotropy and room temperature multiferroic properties of this exotic iron oxide polymorph, make it a perspective material for the development of low power consumption magnetic media storage devices. Extending our recent progress in PLD growth of ε-Fe 2 O 3 on the surface of technologically important nitride semiconductors, we apply reciprocal space tomography by electron and x-ray diffraction to investigate the break of crystallographic symmetry occurring at the oxide-nitride interface resulting in the appearance of anisotropic crystallographic disorder in the sub-100 nm ε-Fe 2 O 3 films. The orthorhombic-on-hexagonal nucleation scenario is shown responsible for the development of a peculiar columnar structure observed in ε-Fe 2 O 3 by means of HRTEM and AFM. The complementary information on the direct and reciprocal space structure of the columnar ε-Fe 2 O 3 films is obtained by various techniques and correlated to their magnetic properties. The peculiar temperature dependence of magnetization studied by the small-field magnetization derivative method and by neutron diffraction reveals the existence of a magnetic softening below 150 K, similar to the one observed earlier solely in nanoparticles. The magnetization reversal in ε-Fe 2 O 3 films probed by X-ray magnetic circular dichroism is found different from the behavior of the bulk averaged magnetization measured by conventional magnetometry. The presented results fill the gap between the numerous studies performed on randomly oriented ε-Fe 2 O 3 nanoparticles and much less frequent investigations of epitaxial epsilon ferrite films with lattice orientation fixed by the substrate., Competing Interests: The authors declare no conflict of interest., (© 2021 The Author(s). Published by National Institute for Materials Science in partnership with Taylor & Francis Group.)

To reveal the in planta behaviour of caesium (Cs), the stable isotope 133 Cs was administered into 3-year-old Cryptomeria japonica seedlings by the application of 133 CsCl aqueous solution to the bark surface. The administered 133 Cs was quantified by ICP-MS measurements, which showed transportation of 133 Cs in an ascending direction in the stem. Distribution of 133 Cs was visualized using freeze-fixed C. japonica woody stem samples and cryo-time-of-flight secondary ion mass spectrometry/scanning electron microscopy (cryo-TOF-SIMS/SEM) analysis. Cryo-TOF-SIMS/SEM visualization suggested that 133 Cs was rapidly transported radially by ray parenchyma cells followed by axial transportation by pith and axial parenchyma cells. Adsorption experiments using powdered C. japonica wood samples and X-ray absorption fine structure (XAFS) analysis suggested that 133 Cs was in the hydrated state following its deposition into tracheid cell walls., (Copyright © 2017. Published by Elsevier B.V.)