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.

scholarly journals Response to Comment on “Spin coating epitaxial films”

Science ◽  
2019 ◽  
Vol 365 (6458) ◽  
pp. eaay3966 ◽  
Author(s):  
Meagan V. Kelso ◽  
Naveen K. Mahenderkar ◽  
Qingzhi Chen ◽  
John Z. Tubbesing ◽  
Jay A. Switzer
Keyword(s):  
Single Crystal ◽  
Spin Coating ◽  
Epitaxial Films ◽  
Background Intensity ◽  
X Ray ◽  
Coated Materials ◽  
Pole Figures ◽  
Ray Patterns

Lu and Tang claim that the spin-coated films in our study are not epitaxial. They assume that all of the background intensity in the x-ray pole figures of the spin-coated materials is due to randomly oriented grains. There is no evidence for randomly oriented grains in the 2θ x-ray patterns. The background intensity in the pole figures is also comparable to the background from the single-crystal substrates, which is inconsistent with their assumption.

Epitaxial Growth of Rare-Earth Gallates on Single-Crystal Oxide Substrates

1998 ◽  
Vol 547 ◽  
Author(s):  
Jonathan S. Morrell ◽  
Ziling B. Xue ◽  
Eliot D. Specht ◽  
David B. Beach
Keyword(s):  
Single Crystal ◽  
Spin Coating ◽  
Epitaxial Films ◽  
Lanthanum Gallate ◽  
Epitaxial Relationship ◽  
Plane Orientation ◽  
Lanthanum Aluminate ◽  
Pole Figures ◽  
Oxide Substrates ◽  
Out Of Plane

AbstractEpitaxial films of lanthanum gallate, praseodymium gallate, and neodymium gallate were prepared on [100] strontium titanate and [100] lanthanum aluminate single crystal substrates using solution techniques. The solutions employed were mixed-metal methoxyethoxides in 2-methoxyethanol. Films were prepared by spin-coating with a partially hydrolyzed solution, followed by firing at 850 °C for 20 minutes in air. Theta/2-theta scans revealed only [h00] reflections and omega scans (rocking curves) indicated good out-of-plane orientation. Pole figures and phi scans revealed good in-plane orientation and a [100] || [100] epitaxial relationship between the film and the substrate.

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.

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.

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)).

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.

scholarly journals Substrate-controlled allotropic phases and growth orientation of TiO2epitaxial thin films

2010 ◽  
Vol 43 (6) ◽  
pp. 1502-1512 ◽  
Author(s):  
V. F. Silva ◽  
V. Bouquet ◽  
S. Députier ◽  
S. Boursicot ◽  
S. Ollivier ◽  
...  
Keyword(s):  
Thin Films ◽  
Single Crystal ◽  
Pulsed Laser Deposition ◽  
Deposition Temperature ◽  
Pulsed Laser ◽  
Laser Deposition ◽  
X Ray Diffraction ◽  
X Ray ◽  
Growth Orientation ◽  
Pole Figures

TiO2thin films were grown by pulsed laser deposition on a wide variety of oxide single-crystal substrates and characterized in detail by four-circle X-ray diffraction. Films grown at 873 K on (100)-oriented SrTiO3and LaAlO3were (001)-oriented anatase, while on (100) MgO they were (100)-oriented. On (110) SrTiO3and MgO, (102) anatase was observed. OnM-plane andR-plane sapphire, (001)- and (101)-oriented rutile films were obtained, respectively. OnC-plane sapphire, the coexistence of (001) anatase, (112) anatase and (100) rutile was found; increasing the deposition temperature tended to increase the rutile proportion. Similarly, films grown at 973 K on (100) and (110) MgO showed the emergence, besides anatase, of (110) rutile. All these films were epitaxically grown, as shown by φ scans and/or pole figures, and the various observed orientations were explained on the basis of misfit considerations and interface arrangement.

Electron Microscopy of Shock Loaded Polycrystalline Beryllium

1974 ◽  
Vol 32 ◽  
pp. 506-507 ◽  
Author(s):  
J. M. Galbraith ◽  
L. E. Murr ◽  
A. L. Stevens
Keyword(s):  
Electron Microscopy ◽  
Wave Propagation ◽  
Structural Change ◽  
Single Crystal ◽  
Diffraction Pattern ◽  
Shock Loading ◽  
Slip Systems ◽  
Compression Tests ◽  
X Ray Diffraction ◽  
X Ray

Uniaxial compression tests and hydrostatic tests at pressures up to 27 kbars have been performed to determine operating slip systems in single crystal and polycrystal1ine beryllium. A recent study has been made of wave propagation in single crystal beryllium by shock loading to selectively activate various slip systems, and this has been followed by a study of wave propagation and spallation in textured, polycrystal1ine beryllium. An alteration in the X-ray diffraction pattern has been noted after shock loading, but this alteration has not yet been correlated with any structural change occurring during shock loading of polycrystal1ine beryllium.This study is being conducted in an effort to characterize the effects of shock loading on textured, polycrystal1ine beryllium. Samples were fabricated from a billet of Kawecki-Berylco hot pressed HP-10 beryllium.

Crystal structure of an inclusion complex between chiral monoaza-15-crown-5 and S(–)-1-phenyl-ethyl ammonium percholorate

2003 ◽  
Vol 218 (5) ◽  
Author(s):  
Süheyla Özbey ◽  
F. B. Kaynak ◽  
M. Toğrul ◽  
N. Demirel ◽  
H. Hoşgören
Keyword(s):  
Crystal Structure ◽  
Inclusion Complex ◽  
Single Crystal ◽  
X Ray Diffraction ◽  
Space Group ◽  
X Ray ◽  
New Type

AbstractA new type of inclusion complex, S(–)-1 phenyl ethyl ammonium percholorate complex of R-(–)-2-ethyl - N - benzyl - 4, 7, 10, 13 - tetraoxa -1- azacyclopentadecane, has been prepared and studied by NMR, IR and single crystal X-ray diffraction techniques. The compound crystallizes in space group

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