scholarly journals A portable molecular beam epitaxy system for in situ x-ray investigations at synchrotron beamlines

2012 ◽  
Vol 83 (10) ◽  
pp. 105112 ◽  
Author(s):  
T. Slobodskyy ◽  
P. Schroth ◽  
D. Grigoriev ◽  
A. A. Minkevich ◽  
D. Z. Hu ◽  
...  
2000 ◽  
Vol 639 ◽  
Author(s):  
Ryuhei Kimura ◽  
Kiyoshi Takahashi ◽  
H. T. Grahn

ABSTRACTAn investigation of the growth mechanism for RF-plasma assisted molecular beam epitaxy of cubic GaN films using a nitrided AlGaAs buffer layer was carried out by in-situ reflection high energy electron diffraction (RHEED) and high resolution X-ray diffraction (HRXRD). It was found that hexagonal GaN nuclei grow on (1, 1, 1) facets during nitridation of the AlGaAs buffer layer, but a highly pure, cubic-phase GaN epilayer was grown on the nitrided AlGaAs buffer layer.


2003 ◽  
Vol 798 ◽  
Author(s):  
V. Katchkanov ◽  
J. F. W. Mosselmans ◽  
S. Dalmasso ◽  
K. P. O'Donnell ◽  
R. W. Martin ◽  
...  

ABSTRACTThe local structure around Er and Eu atoms introduced into GaN epilayers was studied by means of Extended X-ray Absorption Fine Structure above the appropriate rare-earth X-ray absorption edge. The samples were doped in situ during growth by Molecular Beam Epitaxy. The formation of ErN clusters was found in samples with high average Er concentrations of 32±6% and 12.4±0.8%, estimated by Wavelength Dispersive X-ray analysis. When the average Er concentration is decreased to 6.0±0.2%, 1.6±0.2% and 0.17±0.02%, Er is found in localised clusters of ErGaN phase with high local Er content. Similar behaviour is observed for Eu-doped samples. For an average Eu concentration of 30.5±0.5% clusters of pure EuN occur. Decreasing the Eu concentration to 10.4±0.5% leads to EuGaN clusters with high local Eu content. However, for a sample with an Eu concentration of 14.2±0.5% clustering of Eu was not observed.


1999 ◽  
Vol 13 (09n10) ◽  
pp. 991-996
Author(s):  
M. Salvato ◽  
C. Attanasio ◽  
G. Carbone ◽  
T. Di Luccio ◽  
S. L. Prischepa ◽  
...  

High temperature superconducting multilayers have been obtained depositing Bi2Sr2CuO6+δ(2201) and ACuO2 layers, where A is Ca or Sr, by Molecular Beam Epitaxy (MBE) on MgO and SrTiO3 substrates. The samples, formed by a sequence of 2201/ACuO2 bilayers, have different thickness of ACuO2 layers while the thickness of the 2201 layers is kept constant. The surface structure of each layer has been monitored by in situ Reflection High Energy Electron Diffraction (RHEED) analysis which has confirmed a 2D nucleation growth. X-ray diffraction (XRD) analysis has been used to confirm that the layered structure has been obtained. Moreover, one-dimensional X-ray kinematic diffraction model has been developed to interpret the experimental data and to estimate the period of the multilayers. Resistive measurements have shown that the electrical properties of the samples strongly depend on the thickness of the ACuO2 layers.


1991 ◽  
Vol 231 ◽  
Author(s):  
Elizabeth Schuler ◽  
Sezai Elagoz ◽  
William Vavra ◽  
Frank Lamelas ◽  
Hui David He ◽  
...  

AbstractWe describe measurements on the magnetic properties of Co-Cu superlattices in which the Co layer thickness was fixed at 20 Å and the Cu thickness was varied from 4 Å to 24 Å. The samples were grown on Ge-buffered (110) GaAs by molecular beam epitaxy. X-ray scattering and in-situ RHEED indicate that the multilayers are oriented in the (111) direction with the Co layers stacked in an fcc arrangement. Our interest in this series of samples lies in their unusual hysteresis curves which show distinct transitions. We have found that the appearance of these transitions is directly related to the Cu thickness, indicating the presence of complex spin configurations as a consequence of competing interactions. The results are not consistent with a simple RKKY antiferromagnetic coupling.


2005 ◽  
Vol 357 (1-2) ◽  
pp. 165-169 ◽  
Author(s):  
Vladimir M. Kaganer ◽  
Wolfgang Braun ◽  
Bernd Jenichen ◽  
Klaus H. Ploog

2007 ◽  
Vol 78 (7) ◽  
pp. 073908 ◽  
Author(s):  
Shunsuke Ohkouchi ◽  
Yusui Nakamura ◽  
Naoki Ikeda ◽  
Yoshimasa Sugimoto ◽  
Kiyoshi Asakawa

1998 ◽  
Vol 73 (24) ◽  
pp. 3580-3582 ◽  
Author(s):  
Joseph G. Pellegrino ◽  
John Armstrong ◽  
Jeremiah Lowney ◽  
Barbara DiCamillo ◽  
Joseph C. Woicik

1998 ◽  
Vol 5 (3) ◽  
pp. 1038-1040
Author(s):  
Tsuneharu Koide ◽  
Tetsuo Shidara ◽  
Nobuo Nakajima ◽  
Hiroshi Miyauchi ◽  
Hirohito Fukutani

An economical and easily movable molecular-beam epitaxy (MBE) apparatus which prepares magnetic ultrathin films and superlattices with atomically well controlled interfaces has been designed and constructed. Cleaning and characterization of substrates, sample deposition in a layer-by-layer fashion, and characterization of samples both during and after growth can be carried out in a single ultrahigh vacuum (UHV) chamber. This MBE apparatus is combined with UHV high-field magneto-optical instruments for in situ soft X-ray magnetic circular dichroism experiments on two-dimensional magnetic systems.


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