Interfacial Superstructures Studied by Grazing Incidence X-Ray Diffraction

1989 ◽  
Vol 159 ◽  
Author(s):  
Koichi Akimoto ◽  
Jun'Ichiro Mizuki ◽  
Ichiro Hirosawa ◽  
Junji Matsui
Keyword(s):  
Synchrotron Radiation ◽  
Direct Observation ◽  
Molecular Beam ◽  
Solid Phase ◽  
Grazing Incidence ◽  
Deposition Method ◽  
X Ray Diffraction ◽  
X Ray ◽  
Molecular Beam Deposition ◽  
Beam Deposition

ABSTRACTSurface superstructures (reconstructed structures) have been observed by many authors. However, it is not easy to confirm that a superstructure does exist at an interface between two solid layers. The present paper reports a direct observation, by a grazing incidence x-ray diffraction technique with use of synchrotron radiation, of superstructures at the interface. Firstly, the boron-induced R30° reconstruction at the Si interface has been investigated. At the a Si/Si(111) interface, boron atoms at 1/3 ML are substituted for silicon atoms, thus forming a R30° lattice. Even at the interface between a solid phase epitaxial Si(111) layer and a Si(111) substrate, the boron-induced R30° reconstruction has been also observed. Secondly, SiO2/Si(100)-2×l interfacial superstructures have been investigated. Interfacial superstructures have been only observed in the samples of which SiO2 layers have been deposited with a molecular beam deposition method. Finally, the interfaces of MOCVD-grown AIN/GaAs(100) have been shown to have 1×4 and 1×6 superstructures.

Synthesis of Dislocation Free Siy(SnxC1−x)1−y Alloys by Molecular Beam Deposition and Solid Phase Epitaxy

1993 ◽  
Vol 298 ◽  
Author(s):  
Gang He ◽  
Mark D. Savellano ◽  
Harry A. Atwater
Keyword(s):  
Molecular Beam ◽  
Solid Phase ◽  
Solid Phase Epitaxy ◽  
X Ray Diffraction ◽  
Time Resolved ◽  
Pure Silicon ◽  
Ion Channeling ◽  
Transmission Electron ◽  
Molecular Beam Deposition ◽  
Beam Deposition

AbstractSynthesis of strain-compensated single-crystal Siy(SnxC1-x)1-y alloy films on silicon (100) substrates has been achieved with compositions of tin and carbon greatly exceeding their normal equilibrium solubility in silicon. Amorphous SiSnC alloys were deposited by molecular beam deposition from solid sources followed by thermal annealing. In situ monitoring of crystallization was done using time-resolved reflectivity. Good solid phase epitaxy was observed for Si0.98Sn0.01C0.01, at a rate about 20 times slower than that of pure silicon. Compositional and structural analysis was done using Rutherford backscattering, electron microprobe, ion channeling, x-ray diffraction, and transmission electron microscopy.

Molecular multilayers: structure and templating effects

2000 ◽  
Vol 620 ◽  
Author(s):  
Sandrine Heutz ◽  
Sallie M. Bayliss ◽  
Rudi Cloots ◽  
Ruth L. Middleton ◽  
Garry Rumbles ◽  
...  
Keyword(s):  
Molecular Beam ◽  
Double Layers ◽  
X Ray Diffraction ◽  
Multilayered Structures ◽  
X Ray ◽  
Metal Free ◽  
Molecular Beam Deposition ◽  
Polymorphic Forms ◽  
Templating Effect ◽  
Beam Deposition

ABSTRACTPowder X-Ray diffraction (XRD) has been used to study multilayered structures grown by, organic molecular beam deposition based on the molecular materials PTCDA and metal-free phthalocyanine (H2Pc). Double layers of different polymorphic forms (α, β1 and β2) of H2Pc indicate that the structure of the second layer is determined by the properties of the first layer. It is also shown that the first layer completely disrupts the crystallinity of the second layer in heterostructures containing PTCDA and H2Pc. The implication is that a strong templating effect occurs during the growth of multilayer molecular thin film structures.

scholarly journals Grazing-incidence X-ray diffraction of single GaAs nanowires at locations defined by focused ion beams

2013 ◽  
Vol 46 (4) ◽  
pp. 887-892 ◽  
Author(s):  
Genziana Bussone ◽  
Rüdiger Schott ◽  
Andreas Biermanns ◽  
Anton Davydok ◽  
Dirk Reuter ◽  
...  
Keyword(s):  
Gaas Substrate ◽  
Lattice Spacing ◽  
Molecular Beam ◽  
Grazing Incidence ◽  
Lattice Parameter ◽  
Ion Beams ◽  
Focused Ion Beams ◽  
X Ray Diffraction ◽  
X Ray ◽  
Gaas Nanowires

Grazing-incidence X-ray diffraction measurements on single GaAs nanowires (NWs) grown on a (111)-oriented GaAs substrate by molecular beam epitaxy are reported. The positions of the NWs are intentionally determined by a direct implantation of Au with focused ion beams. This controlled arrangement in combination with a nanofocused X-ray beam allows the in-plane lattice parameter of single NWs to be probed, which is not possible for randomly grown NWs. Reciprocal space maps were collected at different heights along the NW to investigate the crystal structure. Simultaneously, substrate areas with different distances from the Au-implantation spots below the NWs were probed. Around the NWs, the data revealed a 0.4% decrease in the lattice spacing in the substrate compared with the expected unstrained value. This suggests the presence of a compressed region due to Au implantation.

Reconstructed Structure of SiO2/Si(111) Interface

1990 ◽  
Vol 208 ◽  
Author(s):  
Ichiro Hirosawa ◽  
Jun'ichiro Nizuki ◽  
Toru Tatsumi ◽  
Koichi Akimoto ◽  
Junji Matsui
Keyword(s):  
Molecular Beam ◽  
Structural Model ◽  
Oxidation Process ◽  
Grazing Incidence ◽  
Interface Structure ◽  
X Ray Diffraction ◽  
Initial Oxidation ◽  
X Ray ◽  
Diffraction Geometry ◽  
Symmetry Structure

ABSTRACTIn order to investigate the initial oxidation process Qf the Si (111) surface, we have studied the molecular beam deposited Si0 2/Si(111)-7×7 interface structure using grazing incidence X-ray diffraction geometry. We suggest a three-fold symmetry structural model composed of stacking fault layer, dimer layer and additional ordered atoms. The three-fold symmetry structure comes from the preference for oxidation in the faulted half of the 7×7 structure.

EPITAXY OF ULTRATHIN CoO FILMS STUDIED BY XPD AND GIXRD

2002 ◽  
Vol 09 (02) ◽  
pp. 937-941 ◽  
Author(s):  
P. LUCHES ◽  
C. GIOVANARDI ◽  
T. MOIA ◽  
S. VALERI ◽  
F. BRUNO ◽  
...  
Keyword(s):  
Synchrotron Radiation ◽  
Lattice Constant ◽  
Photoelectron Spectroscopy ◽  
Grazing Incidence ◽  
X Ray Diffraction ◽  
Direction Parallel ◽  
X Ray ◽  
Photoelectron Diffraction ◽  
Rocksalt Structure ◽  
Plane Lattice

CoO layers have been grown by exposing to oxygen the (001) body-centered-tetragonal (bct) surface of a Co ultrathin film epitaxially grown on Fe(001). Different oxide thicknesses in the 2–15 ML range have been investigated by means of synchrotron-radiation-based techniques. X-ray photoelectron spectroscopy has been used to check the formation of the oxide films; X ray photoelectron diffraction has given information concerning the symmetry of their unit cell; grazing incidence X-ray diffraction has allowed to evaluate precisely their in-plane lattice constant. The films show a CoO(001) rocksalt structure, rotated by 45° with respect to the bct Co substrate, with the [100] direction parallel to the substrate [110] direction. Their in-plane lattice constant increases as a function of thickness, to release the in-plane strain due to the 3% mismatch between the bulk CoO phase and the underlying substrate.

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