Single-crystal PbTiO3/PbZrO3 composite fibers formed by diffusion and epitaxial growth

CrystEngComm ◽  
2014 ◽  
Vol 16 (44) ◽  
pp. 10314-10320
Author(s):  
Tingting Yu ◽  
Zhaohui Ren ◽  
Shan Jiang ◽  
Siyu Gong ◽  
Ming Li ◽  
...  
Keyword(s):  
Single Crystal ◽  
Epitaxial Growth ◽  
Composite Fibers ◽  
Hydrothermal Conditions ◽  
First Time

Single-crystal PbTiO3/PbZrO3 (PT/PZ) composite fibers were prepared under hydrothermal conditions for the first time, which had an epitaxial growth relationship between single-crystal perovskite PT nanofibers and PZ crystals.

EPITAXIAL GROWTH OF SiO2 ON Mo(112)

2000 ◽  
Vol 07 (01n02) ◽  
pp. 7-14 ◽  
Author(s):  
T. SCHROEDER ◽  
M. ADELT ◽  
B. RICHTER ◽  
M. NASCHITZKI ◽  
M. BÄUMER ◽  
...  
Keyword(s):  
Single Crystal ◽  
Epitaxial Growth ◽  
High Contrast ◽  
Silicon Deposition ◽  
Final Annealing ◽  
Subsequent Oxidation ◽  
Control Film ◽  
Annealing Procedure ◽  
First Time

A new preparation is reported which, for the first time, results in a thin, crystalline SiO2 film on a Mo(112) single crystal. The procedure consists of repeated cycles of silicon deposition and subsequent oxidation, followed by a final annealing procedure. AES and XPS have been used to control film stoichiometry. LEED pictures of high contrast show a hexagonal, crystalline SiO2 overlayer with a commensurate relationship to the Mo(112) substrate. The wetting of the substrate by the film has been investigated by LEED, XPS and TDS, revealing that the film covers the substrate completely.

Influence of Metal Substitution on the Pressure-Induced Phase Change in Flexible Zeolitic Imidazolate Frameworks

2018 ◽  
Author(s):  
C. Michael McGuirk ◽  
Tomče Runčevski ◽  
Julia Oktawiec ◽  
Ari Turkiewicz ◽  
mercedes K. taylor ◽  
...  
Keyword(s):  
Phase Change ◽  
Single Crystal ◽  
Gas Adsorption ◽  
High Capacity ◽  
Phase Changes ◽  
Zeolitic Imidazolate Frameworks ◽  
Metal Substitution ◽  
Heat Management ◽  
Metal Organic ◽  
First Time

<p>Metal–organic frameworks that display step-shaped adsorption profiles arising from discrete pressure-induced phase changes are promising materials for applications in both high-capacity gas storage and energy-efficient gas separations. The thorough investigation of such materials through chemical diversification, gas adsorption measurements, and <i>in situ </i>structural characterization is therefore crucial for broadening their utility. We examine a series of isoreticular, flexible zeolitic imidazolate frameworks (ZIFs) of the type M(bim)<sub>2</sub> (SOD; M = Zn<sup> </sup>(ZIF-7), Co (ZIF-9), Cd (CdIF-13); bim<sup>–</sup> = benzimidazolate), and elucidate the effects of metal substitution on the pressure-responsive phase changes and the resulting CO<sub>2</sub> and CH<sub>4</sub> step positions, pre-step uptakes, and step capacities. Using ZIF-7 as a benchmark, we reexamine the poorly understood structural transition responsible for its adsorption steps and, through high-pressure adsorption measurements, verify that it displays a step in its CH<sub>4 </sub>adsorption isotherms. The ZIF-9 material is shown to undergo an analogous phase change, yielding adsorption steps for CO<sub>2</sub> and CH<sub>4</sub> with similar profiles and capacities to ZIF-7, but with shifted threshold pressures. Further, the Cd<sup>2+</sup> analogue CdIF-13 is reported here for the first time, and shown to display adsorption behavior distinct from both ZIF-7 and ZIF-9, with negligible pre-step adsorption, a ~50% increase in CO<sub>2</sub> and CH<sub>4</sub> capacity, and dramatically higher threshold adsorption pressures. Remarkably, a single-crystal-to-single-crystal phase change to a pore-gated phase is also achieved with CdIF-13, providing insight into the phase change that yields step-shaped adsorption in these flexible ZIFs. Finally, we show that the endothermic phase change of these frameworks provides intrinsic heat management during gas adsorption. </p>

Rapid Epitaxial Growth of Si and SiGe Mono-Crystalline Films on Silicon-on-Glass Substrates by Reactive CVD Using SiH4, GeH4, and F2

2012 ◽  
Vol 1426 ◽  
pp. 331-337
Author(s):  
Hiroshi Noge ◽  
Akira Okada ◽  
Ta-Ko Chuang ◽  
J. Greg Couillard ◽  
Michio Kondo
Keyword(s):  
Epitaxial Growth ◽  
Heating Temperature ◽  
Exothermic Reaction ◽  
Epitaxial Films ◽  
Si Substrates ◽  
Glass Substrates ◽  
Good Crystallinity ◽  
Crystalline Films ◽  
Si Films ◽  
First Time

ABSTRACTWe have succeeded in the rapid epitaxial growth of Si, Ge, and SiGe films on Si substrates below 670 ºC by reactive CVD utilizing the spontaneous exothermic reaction between SiH4, GeH4, and F2. Mono-crystalline SiGe epitaxial films with Ge composition ranging from 0.1 to 1.0 have been successfully grown by reactive CVD for the first time.This technique has also been successfully applied to the growth of these films on silicon-on-glass substrates by a 20 - 50 ºC increase of the heating temperature. Over 10 μm thick epitaxial films at 3 nm/s growth rate are obtained. The etch pit density of the 5.2 μm-thick Si0.5Ge0.5 film is as low as 5 x 106 cm-2 on top. Mobilities of the undoped SiGe and Si films are 180 to 550 cm2/Vs, confirming the good crystallinity of the epitaxial films.

scholarly journals An investigation of polyhedral deformation in two mixed-metal diarsenates: SrZnAs2O7and BaCuAs2O7

2015 ◽  
Vol 71 (4) ◽  
pp. 330-337 ◽  
Author(s):  
Sabina Kovač ◽  
Ljiljana Karanović ◽  
Tamara Đorđević
Keyword(s):  
Crystal Structure ◽  
Single Crystal ◽  
General Formula ◽  
Three Dimensional ◽  
X Ray Diffraction ◽  
Hydrothermal Conditions ◽  
X Ray ◽  
Open Framework ◽  
Geometrical Characteristics ◽  
Barium Copper

Two isostructural diarsenates, SrZnAs2O7(strontium zinc diarsenate), (I), and BaCuAs2O7[barium copper(II) diarsenate], (II), have been synthesized under hydrothermal conditions and characterized by single-crystal X-ray diffraction. The three-dimensional open-framework crystal structure consists of corner-sharingM2O5(M2 = Zn or Cu) square pyramids and diarsenate (As2O7) groups. Each As2O7group shares its five corners with five differentM2O5square pyramids. The resulting framework delimits two types of tunnels aligned parallel to the [010] and [100] directions where the large divalent nine-coordinatedM1 (M1 = Sr or Ba) cations are located. The geometrical characteristics of theM1O9,M2O5and As2O7groups of known isostructural diarsenates, adopting the general formulaM1IIM2IIAs2O7(M1II= Sr, Ba, Pb;M2II= Mg, Co, Cu, Zn) and crystallizing in the space groupP21/n, are presented and discussed.

Oxide Mediated Epitaxial Growth of CoSi2 in a Single Deposition Step

1999 ◽  
Vol 564 ◽  
Author(s):  
S. Ohmi ◽  
R. T. Tung
Keyword(s):  
Single Crystal ◽  
Epitaxial Growth ◽  
Diffusion Barrier ◽  
Blocking Layer ◽  
Deposition Step

AbstractA number of modifications of the oxide-mediated epitaxy (OME) technique are presented which have enabled the growth of thick (∼25–40nm) epitaxial CoSi2 layers in a single deposition sequence. The uses of (a) a thin Ti cap, (b) a thin Ti blocking layer, (c) the codeposition of Co-rich CoSix, and (d) the co-deposition of Col−xTix. have all been shown to lead to improved epitaxial quality over the pure Co OME process, for Co thickness greater than 6nm. Essentially uniform, single crystal silicide layers of over 25nm have been grown in a single deposition step. These results are supportive of the proposed role of a diffusion barrier/kinetics retarder on the part of the interlayer in the OME and the Ti-interlayer mediated epitaxy processes.

MOCVD epitaxial growth of single crystal GaN, AlN and AlxGa1-xN

1985 ◽  
Vol 14 (5) ◽  
pp. 633-644 ◽  
Author(s):  
M. Matloubian ◽  
M. Gershenzon
Keyword(s):  
Single Crystal ◽  
Epitaxial Growth

scholarly journals Epitaxial Growth of Co Thin Films on SrTiO3 Single-Crystal Substrates

2010 ◽  
Vol 34 (2) ◽  
pp. 78-91 ◽  
Author(s):  
O. Yabuhara ◽  
Y. Nukaga ◽  
M. Ohtake ◽  
F. Kirino ◽  
M. Futamoto
Keyword(s):  
Thin Films ◽  
Single Crystal ◽  
Epitaxial Growth

Hetero-Epitaxial Growth of 3C-SiC on Silicon Substrates by Plasma Assisted CVD

2006 ◽  
Vol 527-529 ◽  
pp. 299-302
Author(s):  
Hideki Shimizu ◽  
Yosuke Aoyama
Keyword(s):  
Substrate Temperature ◽  
Single Crystal ◽  
Epitaxial Growth ◽  
Deposition Rate ◽  
Crystalline Structure ◽  
Flow Rate ◽  
Silicon Substrates ◽  
High Quality ◽  
Sic Films ◽  
Lower Substrate Temperature

3C-SiC films grown on carbonized Si (100) by plasma-assisted CVD have been investigated with systematic changes in flow rate of monosilane (SiH4) and propane (C3H8) as source gases. The deposition rate of the films increased monotonously and the microstructures of the films changed from 3C-SiC single crystal to 3C-SiC polycrystal with increasing flow rate of SiH4. Increasing C3H8 keeps single crystalline structure but results in contamination of α-W2C, which is a serious problem for the epitaxial growth. To obtain high quality 3C-SiC films, the effects of C3H8 on the microstructures of the films have been investigated by reducing the concentration of C3H8. Good quality 3C-SiC single crystal on Si (100) is grown at low net flow rate of C3H8 and SiH4, while 3C-SiC single crystal on Si (111) is grown at low net flow rate of C3H8 and high net flow rate of SiH4. It is expected that 3C-SiC epitaxial growth on Si (111) will take placed at a higher deposition rate and lower substrate temperature than that on Si (100).

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