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.

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.

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.

scholarly journals Epitaxial Growth of Magnesia Films on Single Crystalline Magnesia Substrates by Atmospheric-Pressure Chemical Vapor Deposition

2016 ◽  
Vol 5 (2) ◽  
pp. 56
Author(s):  
Keiji Komatsu ◽  
Pineda Marulanda David Alonso ◽  
Nozomi Kobayashi ◽  
Ikumi Toda ◽  
Shigeo Ohshio ◽  
...  
Keyword(s):  
Chemical Vapor Deposition ◽  
Single Crystal ◽  
Vapor Deposition ◽  
Atmospheric Pressure ◽  
Reciprocal Lattice ◽  
Chemical Vapor ◽  
X Ray ◽  
Pole Figures ◽  
Out Of Plane ◽  
Pressure Chemical

<p class="1Body">MgO films were epitaxially grown on single crystal MgO substrates by atmospheric-pressure chemical vapor deposition (CVD). Reciprocal lattice mappings and X-ray reflection pole figures were used to evaluate the crystal quality of the synthesized films and their epitaxial relation to their respective substrates. The X-ray diffraction profiles indicated that the substrates were oriented out-of-plane during MgO crystal growth. Subsequent pole figure measurements showed how all the MgO films retained the substrate in-plane orientations by expressing the same pole arrangements. The reciprocal lattice mappings indicated that the whisker film showed a relatively strong streak while the continuous film showed a weak one. Hence, highly crystalline epitaxial MgO thin films were synthesized on single crystal MgO substrates by atmospheric-pressure CVD.</p>

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.

Sol-Gel Synthesis of Epitaxial Films of (Sr,Ba)Bi2(Nb,Ta)2O9 and Bi4Ti3O12 on [100] SrTiO3

1997 ◽  
Vol 495 ◽  
Author(s):  
Jonathan S. Morrell ◽  
Ziling B. Xue ◽  
Eliot D. Specht ◽  
David B. Beach
Keyword(s):  
Spin Coating ◽  
Sol Gel ◽  
Epitaxial Films ◽  
Full Width ◽  
Lattice Constants ◽  
Plane Orientation ◽  
Pole Figures ◽  
Sol Gel Process ◽  
Out Of Plane ◽  
Sol Gel Synthesis

ABSTRACTAn all-alkoxide sol-gel process utilizing methoxyethoxide complexes in 2-methoxyethanol was used to prepare epitaxial films of SrBi2Nb2O9, SrBi2Ta2O9, BaBi2Nb2O9, BaBi2Ta2O9, and Bi4Ti3O12 on [100] oriented SrTiO3 single crystals. Films were prepared by spin coating strontium titanate substrates with partially hydrolyzed alkoxide solutions and firing in air at 850 °C for 20 minutes. Out-of-plane orientation was confirmed by θ-2θ scans which showed only [002ℓ] reflections. In-plane orientation was determined by pole figures and phi-scans about the [105] plane in the case of the (Sr,Ba)Bi2(Nb,Ta)2O9 complexes and the [117] plane in the case of Bi4Ti3O12. Lattice constants and full-width at half-maximum (fwhm) values for both in-plane and out-of-plane reflections are reported.

A low-background-intensity focusing small-angle X-ray scattering undulator beamline

2013 ◽  
Vol 46 (6) ◽  
pp. 1670-1680 ◽  
Author(s):  
Nigel M. Kirby ◽  
Stephen T. Mudie ◽  
Adrian M. Hawley ◽  
David J. Cookson ◽  
Haydyn D. T. Mertens ◽  
...  
Keyword(s):  
Single Crystal ◽  
Background Intensity ◽  
Wide Angle ◽  
Accurate Analysis ◽  
Diverse Range ◽  
X Ray ◽  
X Ray Scattering ◽  
Collimation System ◽  
Scattering Geometry ◽  
Ray Scattering

The SAXS/WAXS beamline at the Australian Synchrotron is an advanced and flexible undulator X-ray scattering beamline used for small- and wide-angle X-ray scattering analysis on a wide variety of solids, fluids and surfaces across a diverse range of research and development fields. The beamline has numerous features that minimize the intensity of the instrument background, provide automated stable optics, and allow accurate analysis of very weakly scattering samples. The geometric and intensity requirements of a three-slit collimation system are described in detail for conventional metal and single-crystal germanium slits. Straightforward ray tracing and simple linear projections describe the observed direct beam as well as parasitic background scattering geometry of the beamline at its longest camera length, providing a methodology for the design and operation of similar beamlines. As an aid to instrument design, the limit of background intensity determined by the intensity incident on single-crystal germanium guard slit edges and itsqdependence was quantified at 11 keV. Details of the beamline's implementation, underlying optical concept and measured performance are given.

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.

Straczekite, a new calcium barium potassium vanadate mineral from Wilson Springs, Arkansas

1984 ◽  
Vol 48 (347) ◽  
pp. 289-293 ◽  
Author(s):  
Howard T. Evans ◽  
Gordon Nord ◽  
John Marinenko ◽  
Charles Milton
Keyword(s):  
Electron Diffraction ◽  
Chemical Analysis ◽  
Single Crystal ◽  
General Formula ◽  
Secondary Mineral ◽  
Calculated Density ◽  
X Ray ◽  
Cell Parameters ◽  
Diffraction Patterns ◽  
Ray Patterns

AbstractStraczekite, a new calcium barium potassium vanadate from Wilson Springs (formerly Potash Sulfur Springs), Arkansas, occurs as a rare secondary mineral in fibrous seams in gangue. The dark greenish-black crystals are very soft, thin laths up to 0.5 mm in length, forming thick masses. No single-crystal X-ray patterns could be obtained, but good electron diffraction patterns yielded a monoclinic unit cell in space group C2/m, C2, or Cm. The cell parameters were refined by least squares analysis of Guinier-Hägg X-ray powder data: a 11.679(2), b 3.6608(4), c 10.636(2)Å, β = 100.53(4)° (strongest lines are: 003, 3.486, 100; 001, 10.449, 50; 020 1.8306, 50; 6̄01/510, 1.9437, 15; 111/2̄03, 3.255, 10; 311/3̄12, 2.492, 10; 021, 1.8030, 10). Chemical analysis yields the formula: (Ca0.39Ba0.31K0.33Na0.11)(V1.594+V6.315+Fe0.103+)O20.02(H2O)2.9. The calculated density is 3.21 g/cm3. The mineral conforms to a series of synthetic vanadium bronzes, typified by Ag1-xV2O5 of known structure. It represents a new series of layer vanadate minerals of general formula MxV8O20·yH2O, similar in properties but distinct from the hewettite series (MxV6O16·yH2O).

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