Antiphase Domain Structures of CdTe on Sapphire Substrates

1987 ◽  
Vol 94 ◽  
Author(s):  
Kenji Maruyama ◽  
Mitsuo Yoshikawa ◽  
Hiroshi Takigawa
Keyword(s):  
Reaction Mechanism ◽  
Strong Correlation ◽  
Surface Reaction ◽  
Antiphase Domain ◽  
Cdte Layer ◽  
Single Domain ◽  
Rocking Curve ◽  
X Ray ◽  
Sapphire Substrates ◽  
Domain Structures

ABSTRACTAntiphase domain (APD) structures have been discovered in CdTe layers grown on (0001) sapphire substrates by MOCVD. To explain APD formation, an obstruction model based on a surface-reaction mechanism has been proposed. The proportion of one-phase domains to the total area varies with the [DETe]/[DMCd] ratio (VI/II ratio). A single-domain CdTe layer can be obtained at a VI/II ratio of 5. The APD structure shows a strong correlation with the crystallinity measured by X-ray. For a single-domain CdTe epilayer, theFWHM of the X-ray rocking curve shows 114 arc seconds and the EPD is 6×10 cm−2

Magnetic Properties of Carbon-Coated Ni Nanoparticles Prepared by Solid-Phase Pyrolysis of Nickel-Phthalocyanine

NANO ◽  
2015 ◽  
Vol 10 (06) ◽  
pp. 1550089 ◽  
Author(s):  
Aram Manukyan ◽  
Armen Mirzakhanyan ◽  
Laszlo Sajti ◽  
Ruben Khachaturyan ◽  
Egor Kaniukov ◽  
...  
Keyword(s):  
Solid Phase ◽  
Carbon Matrix ◽  
Single Domain ◽  
Magnetic Characteristics ◽  
Ni Nanoparticles ◽  
X Ray ◽  
Nickel Phthalocyanine ◽  
Domain Structures ◽  
Carbon Coated ◽  
Composition Structure

Carbon-coated nickel nanoparticles with a mean diameter of 40nm were synthesized via solid-phase pyrolysis of nickel-phthalocyanine. The composition structure and morphology of samples were investigated by scanning and transmission electron microscopy, X-ray diffraction, Raman spectroscopy and energy-dispersive X-ray microanalysis. Magnetic characteristics of samples were measured with a vibrational magnetometer and a magnetic resonance spectrometer. The main mass of Ni ferromagnetic nanoparticles have a single-domain and a vortex (pseudo-single domain) structures. We also revealed superparamagnetic Ni nanoparticles (several percent) and carbon paramagnetic centers caused by defects in the carbon matrix. We determined the main magnetic characteristics of Ni nanoparticles, their temperature and field dependences as well as the parameters of ferromagnetic resonance spectra.

Comparison of the Microstructure of AlN Films Grown by MOCVD and by PLD on Sapphire Substrates

1996 ◽  
Vol 449 ◽  
Author(s):  
Yun-Xin Li ◽  
Lourdes Salamanca-Riba ◽  
V. Talyan ◽  
T. Venkatesan ◽  
C. Wongchigul ◽  
...  
Keyword(s):  
Low Density ◽  
Full Width ◽  
High Crystalline Quality ◽  
Rocking Curve ◽  
X Ray ◽  
Force Microscopy ◽  
Sapphire Substrates ◽  
Atomic Force ◽  
Film Substrate ◽  
Microscopy Images

ABSTRACT(0001) aluminium nitride thin films were grown epitaxially on (0001) Sapphire substrates by MOCVD at 1200° C and PLD at 800° C. Both films have the same epitaxial growth relationship: (0001)AlN//(0001)Sap, and the same in-plane relationship which shows a 30° rotation between A1N and Sapphire: [ 12 10]AlN//[0 110]Sap and [10 10]AlN //[ 2110]Sap. The full width at half maximum (FWHM) of x-ray rocking curve of the MOCVD A1N film was 0.16° and PLD A1N film was 0.2°. Films grown by both MOCVD and PLD showed high crystalline quality. HRTEM images showed that these films are single crystalline with very low density of defects.Dislocations in the film parallel to the film / substrate interface were observed in both A1N films. Atomic force microscopy images showed that the MOCVD films have flatter and larger terraces than the PLD films. The PLD technique for A1N growth needs to be improved further. But both films have a surface roughness of approximately 100nm.

Characterization of lattice mosaic ofa-plane GaN grown onr-plane sapphire by metalorganic vapor-phase epitaxy

2005 ◽  
Vol 892 ◽  
Author(s):  
Kazuhide Kusakabe ◽  
Shizutoshi Ando ◽  
Kazuhiro Ohkawa
Keyword(s):  
High Resolution ◽  
Vapor Phase ◽  
Metalorganic Vapor Phase Epitaxy ◽  
Vapor Phase Epitaxy ◽  
Morphological Transition ◽  
X Ray Diffraction ◽  
Rocking Curve ◽  
X Ray ◽  
Sapphire Substrates

AbstractNonpolara-plane GaN films were grown on r-plane sapphire substrates by atmospheric metalorganic vapor-phase epitaxy. The as-grown layers were studied by high-resolution x-ray diffraction. Thea-plane GaN lattice mosaic is orientation dependent as determined by x-ray rocking curve (XRC) measurements. The tilt mosaic measured with the c-axis within the scattering plane (c-mosaic) was greater than the mosaic measured with the m-axis within the scattering plane (m-mosaic). The mosaic along both azimuths decreased and thec-mosaic/m-mosaic ratio was increased with increase of growth temperature from 1050 °C to 1080 °C. The morphological transition was correlated to change in thea-plane GaN tilt mosaic measured by XRC.

Schottky I-V Characteristics of Au/Ni/GaN/SiNx nanonework/sapphire structures

2006 ◽  
Vol 955 ◽  
Author(s):  
Jinqiao Xie ◽  
Yi Fu ◽  
Hadis Morkoç
Keyword(s):  
Vapor Deposition ◽  
Metalorganic Chemical Vapor Deposition ◽  
Schottky Diodes ◽  
Chemical Vapor ◽  
Rocking Curve ◽  
X Ray ◽  
Sapphire Substrates ◽  
Control Samples

ABSTRACTGaN layers on sapphire substrates were grown by metalorganic chemical vapor deposition using in situ porous SiNx nano-network. Crystalline quality of epilayers was characterized by X-ray rocking curve scans, and the full width at hall maximum values for (002) and (102) diffractions were improved from 252 arc sec and 405 arc sec, respectively, in control samples to 216 arc sec and 196 arc sec when SiNx was used. Ni/Au Schottky diodes (SDs) were fabricated and the SD performance was found to be critically dependent on the SiNx coverage (fewer and farther the pores the better the results) which is consistent with the trends of XRD and photoluminescence data. A 1.13eV barrier height was achieved when 5min SiNx layer was used compared with 0.78 eV without any SiNx nanonetwork. Furthermore, the breakdown voltage improved from 76 V to 250V when SiNx nanonetwork was used in otherwise identical structures.

Si and Mg Doped Gan Layers Grown by Gas Source Molecular Beam Epitaxy Using Ammonia

1997 ◽  
Vol 482 ◽  
Author(s):  
N. Grandjean ◽  
J. Massies ◽  
M. Leroux
Keyword(s):  
Molecular Beam Epitaxy ◽  
Molecular Beam ◽  
X Ray Diffraction ◽  
Rocking Curve ◽  
Light Emitting ◽  
X Ray ◽  
Sapphire Substrates ◽  
Gas Source ◽  
P Type ◽  
Mg Doped

AbstractThe growth of GaN layers was carried out on c-plane sapphire substrates by molecular beam epitaxy (MBE) using NH3. Undoped GaN layers were grown at 830°C with growth rates larger than 1 μm/h. Optical properties are characteristics of high quality GaN material and the linewidth of x-ray diffraction (0002) rocking curve is less than 350 arcsec. N- and p-type doping were achieved by using solid sources of Si and Mg. No post-growth annealing was needed to activate the Mg acceptors. As-grown GaN:Mg layers exhibit hole concentrations of 3×1017 cm−3and mobilities of 8 cm2/Vs at 300 K. Light emitting diodes (LEDs) based on GaN p-n homojunction have been processed. The turn on voltage is 3 V and the forward voltage is 3.7 V at 20 mA. The 300 K electroluminescence (EL) peaks at 390 nm.

Preparation and Characterization of Sol-Gel Derived Heteroepitaxial LiNbO3 and LiTaO3 Thin Films

1993 ◽  
Vol 310 ◽  
Author(s):  
Keiichi Nashimoto
Keyword(s):  
Thin Films ◽  
Sol Gel ◽  
Metal Alkoxide ◽  
Bulk Single Crystal ◽  
Rocking Curve ◽  
X Ray ◽  
Sapphire Substrates ◽  
Sol Gel Process ◽  
Alkoxide Precursors

AbstractDense epitaxial LiNbO3 thin films without any misoriented plane on sapphire substrates were obtained with a sol-gel process utilizing 2-methoxyethanol based metal alkoxide precursors without pre-hydrolysis and rapid thermal annealing. Epitaxial LiNbO3 films annealed at 700°C were transparent and showed refractive indices close to bulk single crystal values. Epitaxial and transparent LiTaO3 films crystallized successfully on sapphire substrates with single orientations with the present process. X-ray rocking curve full widths at half maximum of epitaxial LiNbO3 and LiTaO3 films on sapphire (110) substrates and annealed at 700°C were less than 0.4 degree.

scholarly journals MOVPE growth optimization of high quality InGaN films.

1997 ◽  
Vol 2 ◽  
Author(s):  
W. Van der Stricht ◽  
I. Moerman ◽  
P. Demeester ◽  
L. Considine ◽  
E. J. Thrush ◽  
...  
Keyword(s):  
Rotating Disk ◽  
Vapour Phase ◽  
Band Edge Emission ◽  
Edge Emission ◽  
High Quality ◽  
Vapour Phase Epitaxy ◽  
Rocking Curve ◽  
X Ray ◽  
Growth Optimization ◽  
Sapphire Substrates

In this paper growth of high quality InGaN films on (0001) sapphire substrates by atmospheric pressure organometallic vapour phase epitaxy in a vertical rotating disk reactor is investigated. The InGaN layers grown above 800 °C are transparent and show no In-droplets on the surface. The In-content varies between 56 and 9 % for growth temperatures between 700 and 850 °C. The DC X-ray rocking curve of InGaN typically shows a FWHM between 8 and 15 arcmin. Room temperature PL shows an intense band edge emission with a FWHM between 100 and 200 meV for an In-content of 9 and 56 %. The initial efforts on QW growth are discussed.

Pole Figure Analysis of Epitaxial Films of ZnO:2wt%Al Grown on Sapphire Substrates by RF Magnetron Sputtering

2002 ◽  
Vol 721 ◽  
Author(s):  
P. Kuppusami ◽  
S. Fiechter ◽  
K. Ellmer
Keyword(s):  
Magnetron Sputtering ◽  
Pole Figure ◽  
Room Temperature ◽  
Defect Density ◽  
Rf Magnetron Sputtering ◽  
Epitaxial Films ◽  
X Ray Diffraction ◽  
Rocking Curve ◽  
X Ray ◽  
Sapphire Substrates

AbstractAluminium-doped zinc oxide (ZnO:Al) films have been grown on c-plane (001) and a-plane (110) sapphire by RF magnetron sputtering from a ceramic target. The films grew epitaxially, even at room temperature. However, the crystalline quality depends both on the substrate temperature as well as on the sapphire orientation. The best films, proved by X-ray diffraction (rocking curves and pole figure measurements) were grown on (110)-oriented sapphire in the temperature range 473 to 773 K. The minimum rocking curve half width was about 0.75 °. By Rutherford backscattering analysis it could be shown, that the films exhibit a significant variation of the defect density over the film thickness. The highest density, as expected, is observed at the interface sapphire/ZnO:Al. Films grown on (001)-oriented sapphire have higher rocking curve half widths (about 1.3 °) and exhibit sometimes two types of domains in the same film twisted by 30 °.

An X-Ray Study of Domain Structure and Stress in Pd2Si Films at Pd-Si Interfaces

1981 ◽  
Vol 10 ◽  
Author(s):  
Haydn Chen ◽  
G. E. White ◽  
S. R. Stock ◽  
P. S. Ho
Keyword(s):  
Plastic Deformation ◽  
Domain Structure ◽  
Silicon Substrates ◽  
Silicide Formation ◽  
X Ray Diffraction ◽  
Rocking Curve ◽  
X Ray ◽  
Crystallographic Relationship ◽  
Domain Structures ◽  
Pole Figures

The domain structures of palladium and Pd2Si as well as their crystallographic relationship to the silicon substrates were determined on Si(111) and Si(100) samples by mapping X-ray diffraction pole figures. X-ray diffraction topography and rocking curve measurements were carried out for the silicon substrates in order to detect the presence of elastic and/or plastic deformation in the substrates caused by silicide formation. The stresses in the silicide films were determined from the bending of the silicon substrates using X-ray diffraction techniques.

Ultra-Smooth ZnO Buffer Layers on (001) Sapphire

1997 ◽  
Vol 482 ◽  
Author(s):  
A. J. Drehman ◽  
S.-Q. Wang ◽  
P. W. Yip
Keyword(s):  
Buffer Layers ◽  
Zno Films ◽  
Potential Candidate ◽  
X Ray Diffraction ◽  
Rocking Curve ◽  
X Ray ◽  
Force Microscopy ◽  
Sapphire Substrates ◽  
Atomic Force ◽  
Electrical Resistivities

AbstractUsing off-axis reactive rf sputtering, we have grown extremely smooth, nearly epitaxial, (001) oriented ZnO films on c-axis sapphire substrates. Atomic Force Microscopy was used to determine that these films are extremely smooth, having an rms roughness of only a few tenths of a nanometer. Based on high resolution x-ray diffraction (HXRD), the ZnO is highly oriented, with a rocking curve width of less than 400 arc seconds for the (006) diffraction peak, and only somewhat larger for the (112) reflection. HXRD Phi scans show that the ZnO (112) reflection is rotated in the a-b plane by 30 degrees from the sapphire (113) direction. These two measurements indicate excellent in-plane orientation. We are investigating the use of these buffer layers for subsequent GaN growth. Electrical resistivities of the films exceeded 100 kΩ-cm making ZnO a potential candidate as an insulating buffer layer.

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