Epitaxial Growth of CaxSr1−xF2 Layers on CaF2 by Vacuum Evaporation

1985 ◽  
Vol 54 ◽  
Author(s):  
Nicholas G. Norton ◽  
K. S. Knight
Keyword(s):  
Single Crystal ◽  
Optical Microscopy ◽  
Epitaxial Growth ◽  
Single Phase ◽  
Epitaxial Films ◽  
Mixed Crystals ◽  
X Ray Diffraction ◽  
X Ray ◽  
Vegard’S Law ◽  
Substrate Temperatures

ABSTRACTThe evaporation and epitaxial growth on single crystal CaF2 substrates of CaF2/SrF2 mixtures are investigated. The evaporated films are studied with X-ray diffraction and optical microscopy.X-ray diffraction results show that the evaporation of yCaF2 + (1 - y)SrF2 mixtures from a single boat, with y in the range 0 to 1, result in single phase, mixed crystals of composition CaxSr1−xF2. If Vegard's law is assumed to apply it is found experimentally that the film composition is the same as that of the source.For the evaporation of CaF2 and SrF2 onto cleaved CaF2 crystals it is shown that the best quality epitaxial films are obtained at substrate temperatures of∼400°C. At temperatures <400°C there is some broadening of the X-ray diffraction spots from the overlayer compared with those from the substrate. At temperatures>400°C there is a tendency for the epitaxial films to delaminate from the substrate.

Epitaxial growth of PbTiO3 thin films on {100} SrTiO3 from solution precursors

1994 ◽  
Vol 52 ◽  
pp. 576-577
Author(s):  
Andreas Seifert
Keyword(s):  
Thin Films ◽  
Single Crystal ◽  
Single Phase ◽  
Amorphous Solid ◽  
Epitaxial Films ◽  
Gravimetric Analysis ◽  
Layer Formation ◽  
X Ray Diffraction ◽  
X Ray ◽  
Solid Film

A mixed Pb-Ti-alkoxide liquid precursor, prepared from lead acetate and titanium iso-propoxide was used to form single crystal PbTiO3 thin films epitaxially on {100} SrTiO3 substrates.A gravimetric analysis of the precursor determined its molarity to 0.55 mol/1 and was carried out by drying the alkoxide overnight and heating it to 600° C for one hour. X-ray diffraction showed the resulting PbTiO3 powder to be single phase perovskite. PbTiO3 thin films were formed by spincoating previously annealed (1400°C, 2h) single crystal SrTiO3 substrates. During this process the precursor dries to a gel-like amorphous solid film that pyrolizes and crystallizes to the oxide during heat-treatment. XRD, SEM, TEM and AFM were used to characterize the progress of the epitaxial layer formation as well as the microstructural evolution of films heated at increasing temperatures, ranging from 400°C to 800°C. For XRD Θ-2Θ scans on PbTiO3 thin films heated at temperatures of 450°C and above, only the {00l} tetragonal PbTiO3 reflections (CPTO=0.4153 nm) could be observed, indicating strongly oriented or epitaxial films ({h00} of PbTiO3 (aPTO=0.3899 nm) is masked by (MX)} of the SrTiO3 substrate (aSTO=0.3904 nm)).

scholarly journals High pressure studies of L-Serine-L-Ascorbic acid co-crystal

2014 ◽  
Vol 70 (a1) ◽  
pp. C988-C988
Author(s):  
Sergey Arkhipov ◽  
Boris Zakharov ◽  
Elena Boldyreva
Keyword(s):  
High Pressure ◽  
Ascorbic Acid ◽  
Hydrogen Bonds ◽  
Single Crystal ◽  
Crystal Engineering ◽  
Mixed Crystals ◽  
Study Phase ◽  
X Ray Diffraction ◽  
X Ray ◽  
Wide Range

"Experiments for studying crystalline materials under extreme conditions are a powerful tool for investigating ""structure-property"" relationships. They also give information on the behavior of hydrogen bonds and are important both for materials science and crystal engineering. In addition, many processes in the living organisms are also related to mechanical stress. One of the most interesting tasks is to identify factors which influence the stability of a structure, or a part of the structure, at high pressure. Experiments on the systematic study of compounds in a wide range of pressures allow us to accumulate data that can be used to solve this problem. For a more complete picture, the mixed crystals of the selected compound are studied. Investigation of mixed crystals and cocrystals of interest can be compared with the crystals of individual compounds. We have chosen the structure of L-serine - L-ascorbic acid to be compared with those of L-serine and L-ascorbic acids for such a study. Phase transitions were previously reported to be induced by increasing pressure in both L-serine [1] and L-ascorbic acid [2]; moreover, the structure of L-serine was followed at multiple pressures by single-crystal and powder X-ray diffraction[3]. L-serine – L-ascorbic acid co-crystal was studied in the pressure range 0-5.4 GPa (at multiple points at every 0.5-0.7 GPa) by single-crystal X-ray diffraction and Raman spectroscopy. A phase transition has been detected and some rearrangement in the network of hydrogen bonds was observed. The high pressure data were compared with those for the individual structures of the L-serine and L-ascorbic acid. This work was supported by RFBR (grants 12–03-31541, 14-03-31866, 13-03-92704, 14-03-00902 ), Ministry of Science and Education of Russia and Russian Academy of Sciences."

Epitaxial Growth of MgO Single Crystal Thin Film in Oxygen Atmosphere

1992 ◽  
Vol 279 ◽  
Author(s):  
M. H. Yang ◽  
C. P. Flynn
Keyword(s):  
Thin Films ◽  
Single Crystal ◽  
Epitaxial Growth ◽  
Bulk Diffusion ◽  
Oxygen Atmosphere ◽  
Mass Action ◽  
X Ray Diffraction ◽  
X Ray ◽  
Diffusion Studies ◽  
Mgo Substrate

ABSTRACTWe have studied the epitaxial growth of MgO single crystal thin films by depositing Mg onto MgO substrates in an oxygen atmosphere. This method provides a simple way to dope Mg18O layers uniformly into Mg16O. The well controlled layer thicknesses are suitable for bulk diffusion studies both in the MgO epilayer and the MgO substrate. The MgO growth rate was measured and found to be proportional to the Mg flux and to the square root of oxygen pressure at a given temperature, obeying the law of mass action. High quality MgO single crystal thin films, as indicated by RHEED and x-ray diffraction, were found to grow over u wide temperature range, as in the earlier work1 using e-beam evaporation.

Nd3+ Doped LiCaAIF6 Single Crystal for Scintillator Application

2012 ◽  
Vol 508 ◽  
pp. 224-229 ◽  
Author(s):  
Takayuki Yanagida ◽  
Yoshisuke Futami ◽  
Noriaki Kawaguchi ◽  
Jan Pejchal ◽  
Yutaka Fujimoto ◽  
...  
Keyword(s):  
Single Crystal ◽  
Diffraction Analysis ◽  
Luminescence Spectrum ◽  
Single Phase ◽  
Grown Crystal ◽  
Light Yield ◽  
Transmittance Spectrum ◽  
X Ray Diffraction ◽  
X Ray ◽  
The Absolute

ααΑαNd3+ 0.5% Doped Single Crystal LiCaAlF6 Scintillator Was Grown by the Micro-Pulling down (µ-PD) Method. Powder X-Ray Diffraction Analysis Was Done and the Grown Crystal Was a Single Phase LiCaAlF6. it Was Cut and Polished to the Physical Dimension of 1 × 2 × 7 mm3. in Transmittance Spectrum, Nd3+ 5d-4f Absorption Observed at 175 Nm and the Transmittance Became 80% at Wavelength Longer than 180 Nm. Excited by 160 Nm, Nd3+ 5d-4f Emission Appeared at 180 Nm. X-Ray Induced Radio-Luminescence Spectrum Showed the Similar Feature with the Photoluminescence One. when Coupled with PMT and Irradiated by 241Am α-Ray, the Absolute Light Yield Resulted 100 Ph/5.5 Mev α.

Growth of epitaxial films of sodium potassium tantalate and niobate on single-crystal lanthanum aluminate [100] substrates

2008 ◽  
Vol 23 (12) ◽  
pp. 3281-3287 ◽  
Author(s):  
George H. Thomas ◽  
Eliot D. Specht ◽  
John Z. Larese ◽  
Ziling B. Xue ◽  
David B. Beach
Keyword(s):  
Single Crystal ◽  
Lattice Mismatch ◽  
Epitaxial Films ◽  
Metal Species ◽  
Gravimetric Analysis ◽  
X Ray Diffraction ◽  
Sodium Potassium ◽  
Potassium Tantalate ◽  
X Ray ◽  
Lanthanum Aluminate

Epitaxial films of sodium potassium tantalate (Na0.5K0.5TaO3, NKT) and sodium potassium niobate (Na0.5K0.5NbO3, NKN) were grown on single-crystal lanthanum aluminate (LAO) (100) (indexed as a pseudo-cubic unit cell) substrates via an all-alkoxide solution (methoxyethoxide complexes in 2-methoxyethanol) deposition route for the first time. X-ray diffraction studies indicated that the onset of crystallization in powders formed from hydrolyzed gel samples was 550 °C. 13C nuclear magnetic resonance studies of solutions of methoxyethoxide complexes indicated that mixed-metal species were formed, consistent with the low crystallization temperatures observed. Thermal gravimetric analysis with simultaneous mass spectrometry showed the facile loss of the ligand (methoxyethoxide) at temperatures below 400 °C. Crystalline films were obtained at temperatures as low as 650 °C when annealed in air. θ-2θ x-ray diffraction patterns revealed that the films possessed c-axis alignment in that only (h00) reflections were observed. Pole-figures about the NKT or NKN (220) reflection indicated a single in-plane, cube-on-cube epitaxy. The quality of the films was estimated via ω (out-of-plane) and φ (in-plane) scans and full-widths at half-maximum (FWHMs) were found to be reasonably narrow (∼1°), considering the lattice mismatch between the films and the substrate.

scholarly journals Tuning the optical isotropic point of mixed crystals of ethylenediammonium sulfate/selenate

2020 ◽  
Vol 53 (1) ◽  
pp. 51-57
Author(s):  
Melissa Tan ◽  
Alexander T. Martin ◽  
Alexander G. Shtukenberg ◽  
Bart Kahr
Keyword(s):  
Solid Solution ◽  
Single Crystal ◽  
Mueller Matrix ◽  
Mixed Crystals ◽  
Refractive Indices ◽  
Linear Birefringence ◽  
Solid Solution Series ◽  
X Ray Diffraction ◽  
X Ray ◽  
Isotropic Point

In anisotropic crystals, optical isotropic points are wavelengths where linear birefringence disappears because the refractive indices for both eigenmodes are accidentally equivalent. Here, the optical isotropic point of ethylenediammonium selenate (EDSe) is tuned by generating a solid-solution series of EDSe doped with sulfate. Mueller matrix polarimetry and single-crystal X-ray diffraction are used to correlate changes in linear birefringence with the crystal composition of EDS x Se1−x . A scheme for using mixed crystals with isotropic points as tunable birefringent optical bandpass filters is proposed and their performance is modeled.

scholarly journals Comment on “Spin coating epitaxial films”

Science ◽  
2019 ◽  
Vol 365 (6458) ◽  
pp. eaay3894
Author(s):  
Chaojing Lu ◽  
Lingli Tang
Keyword(s):  
Single Crystal ◽  
Spin Coating ◽  
Epitaxial Films ◽  
X Ray Diffraction ◽  
X Ray ◽  
Pole Figures

Kelso et al. (Reports, 12 April 2019, p. 166) claim that inorganic epitaxial films were deposited onto single-crystal or single-crystal–like substrates by spin coating. The epitaxial relationships were determined by x-ray diffraction. According to their pole figures, we estimate that each of their films contains only 4.1% to 25.5% epitaxial grains. None of their films can be considered epitaxial.

Complex Study of SiC Epitaxial Films

2013 ◽  
Vol 740-742 ◽  
pp. 593-596
Author(s):  
E.M. Geyfman ◽  
V.V. Chibirkin ◽  
G.Yu. Kamentsev ◽  
N.A. Gartsev ◽  
N.M. Davydova ◽  
...  
Keyword(s):  
Optical Microscopy ◽  
Epitaxial Films ◽  
X Ray Diffraction ◽  
X Ray ◽  
Complex Study ◽  
Stylus Profiler

4H-SiC epitaxial films grown on 4H-SiC in CVD reactor VP508GFR are investigated using FTIR, X-Ray diffraction, C-V measurements, stylus profiler and DIC optical microscopy.

Synthesis of Epitaxial Thin-Films of Tetragonal Perovskites Via a Solution Technique

1998 ◽  
Vol 547 ◽  
Author(s):  
David B. Beach ◽  
Jonathan S. Morrell ◽  
Ziling B. Xue ◽  
Eliot D. Specht
Keyword(s):  
Thin Films ◽  
Single Crystal ◽  
Epitaxial Films ◽  
Solution Chemistry ◽  
Solution Technique ◽  
Epitaxial Thin Films ◽  
X Ray Diffraction ◽  
X Ray ◽  
Spin Casting

AbstractSolution chemistry has been used to synthesize epitaxial films of SrLaGaO4, SrPrGaO4, SrLaAlO4, and SrPrAlO4 on single crystal substrates of [100] SrTiO3 and [100] LaAlO3. Precursor solutions were prepared from metal methoxyethoxides in 2-methoxyethanol. Films were prepared by spin-casting from partially hydrolyzed solutions followed by firing for 20 minutes in air at 850°C. The structure of the films was determined using X-ray diffraction. Theta/2-theta scans and omega scans (rocking curves) indicated that the films were c-axis aligned. Phi scans proved that the films were also aligned in-plane.

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