Selective Growth of Si Crystals over Amorphous Substrates Seeded by Solid-State Agglomeration of Patterned Si

1989 ◽  
Vol 164 ◽  
Author(s):  
K. Yamagata ◽  
T. Yonehara
Keyword(s):  
Solid State ◽  
Grain Boundary ◽  
Single Crystals ◽  
Substrate Surface ◽  
Selective Growth ◽  
Growth Technique ◽  
Selective Epitaxial Growth ◽  
Amorphous Substrates ◽  
Crystalline Forms ◽  
Specific Orientation

AbstractSelective growth of Si crystals over amorphous substrates, seeded by agglomerated single domained Si crystals is demonstrated. In this method, Si crystal seeds are periodically placed and selectively overgrown until impingement upon adjacent crystals, resulting in a matrix of large Si islands with controlled grain boundary locations. Si seeds are formed over amorphous SiO2 by the solid-state agglomeration phenomenon, and grown selectively up to 100 μm by CVD selective epitaxial growth technique. The grown crystals are classified in three crystalline forms of single crystals, primary twins, and multiple twins. However, most are single crystals with a specific orientation of (110) normal to the substrate surface.

Control of Grain Boundary Location By Selective Nucleation Over Amorphous Substrates

1987 ◽  
Vol 106 ◽  
Author(s):  
T. Yonehara ◽  
Y. Nishigaki ◽  
H. Mizutani ◽  
S. Kondoh ◽  
K. Yamagata ◽  
...  
Keyword(s):  
Crystal Growth ◽  
Grain Boundary ◽  
Small Area ◽  
Substrate Surface ◽  
Growth Technique ◽  
Nucleation Sites ◽  
Amorphous Substrates ◽  
Boundary Location

ABSTRACTA selective nucleation based crystal-growth-technique over amorphous substrates is originated. The method manipulates nucleation sites and periods and hence, controls the grain boundary location by modifing the substrate surface. In Si, small Si3 N4 nucleation sites are formed, 1–2 pm in diameter, 100 μm in period, over Sio2. One Si nucleus is formed exclusively in the small area of Si3 N4 by CVD. The highly faceted and periodically located nuclei grow over SiO2 up to 100 μm in diameter before impingement. A MOS-FET fabricated inside the island operates comparably to the bulk Si control

scholarly journals Growth of single crystals in the (Na1/2Bi1/2)TiO3–(Sr1–xCax)TiO3 system by solid state crystal growth

2021 ◽  
Author(s):  
Phan Gia Le ◽  
Huyen Tran Tran ◽  
Jong-Sook Lee ◽  
John G. Fisher ◽  
Hwang-Pill Kim ◽  
...  
Keyword(s):  
Crystal Growth ◽  
Solid State ◽  
Single Crystal ◽  
Single Crystals ◽  
Piezoelectric Properties ◽  
Single Crystal Growth ◽  
Crystal Growth Rate ◽  
Large Strains ◽  
Growth Technique ◽  
The Matrix

AbstractCeramics based on (Na1/2B1/2)TiO3 are promising candidates for actuator applications because of large strains generated by an electric field-induced phase transition. For example, the (1−x)(Na1/2Bi1/2)TiO3-xSrTiO3 system exhibits a morphotropic phase boundary at x = 0.2–0.3, leading to high values of inverse piezoelectric constant d*33, which can be further improved by the use of single crystals. In our previous work, single crystals of (Na1/2B1/2)TiO3-SrTiO3 and (Na1/2B1/2)TiO3-CaTiO3 were grown by the solid state crystal growth technique. Growth in the (Na1/2B1/2)TiO3-SrTiO3 system was sluggish whereas the (Na1/2B1/2)TiO3-CaTiO3 single crystals grew well. In the present work, 0.8(Na1/2Bi1/2)TiO3-0.2(Sr1−xCax)TiO3 single crystals (with x = 0.0, 0.1, 0.2, 0.3, 0.4) were produced by the solid state crystal growth technique in an attempt to improve crystal growth rate. The dependence of mean matrix grain size, single crystal growth distance, and electrical properties on the Ca concentration was investigated in detail. These investigations indicated that at x = 0.3 the matrix grain growth was suppressed and the driving force for single crystal growth was enhanced. Replacing Sr with Ca increased the shoulder temperature Ts and temperature of maximum relative permittivity Tmax, causing a decrease in inverse piezoelectric properties and a change from normal to incipient ferroelectric behavior.

Zum Mineral Johillerit verwandte Oxovanadate RbCd4V3O12 und TlCd4V3O12 / Oxovanadates RbCd4V3O12 and TlCd4V3 O12 Related to the Mineral Johillerite

1997 ◽  
Vol 52 (5) ◽  
pp. 663-668 ◽  
Author(s):  
B. Mertens ◽  
Hk. Müller-Buschbaum
Keyword(s):  
Crystal Structure ◽  
Solid State ◽  
Single Crystals ◽  
Solid State Reactions ◽  
Space Group ◽  
Related Compounds

Abstract Single crystals of I RbCd4V3O12 and TlCd4V3O12 II have been prepared by solid state reactions in closed iron tubes. The compounds crystallize closely related to the Johillerite structure in the space group C62h- C2/c with I: a = 13.058(3); b - 13.528(3), c = 7 .0 6 0 (2 )Å , β = 114.88(2)°; II: a = 12.999(6), b = 13.527(7), c = 7.055(3) Å , β = 114.88(4)°, Z = 4. Special features are the loss of Cu2+ in order to gain an additional Cd2+ position. The crystal structure is discussed with respect to related compounds of the Johillerite type.

scholarly journals Reduced Viscosity of Mg2GeO4 with Minor MgGeO3 between 1000 and 1150 °C Suggests Solid-State Lubrication at the Lithosphere–Asthenosphere Boundary

Minerals ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 600
Author(s):  
Thomas Ferrand ◽  
Damien Deldicque
Keyword(s):  
Solid State ◽  
Grain Boundary ◽  
Metastable Phase ◽  
Viscosity Reduction ◽  
Tectonic Plates ◽  
Deformation Curves ◽  
Low Viscosity ◽  
Plasma Sintering ◽  
Stress Strain Relation ◽  
Spark Plasma

Tectonic plates are thought to move above the asthenosphere due to the presence of accumulated melts or volatiles that result in a low-viscosity layer, known as lithosphere–asthenosphere boundary (LAB). Here, we report experiments suggesting that the plates may slide through a solid-state mechanism. Ultrafine-grained aggregates of Mg2GeO4 and minor MgGeO3 were synthetized using spark plasma sintering (SPS) and deformed using a 1-atm deformation rig between 950 °C and 1250 °C. For 1000 < T < 1150 °C, the derivative of the stress–strain relation of the material drops down to zero once a critical stress as low as 30–100 MPa is reached. This viscosity reduction is followed by hardening. The deformation curves are consistent with what is commonly observed in steels during the shear-induced transformation from austenite to martensite, the final material being significantly harder. This is referred to as TRansformation-Induced Plasticity (TRIP), widely observed in metal alloys (TRIP alloys). It should be noted that such enhanced plasticity is not necessarily due to a phase transition, but could consist of any kind of transformation, including structural transformations. We suspect a stress-induced grain-boundary destabilization. This could be associated to the transient existence of a metastable phase forming in the vicinity of grain boundaries between 1000 and 1150 °C. However, no such phase can be observed in the recovered samples. Whatever its nature, the rheological transition seems to occur as a result of a competition between diffusional processes (i.e., thermally activated) and displacive processes (i.e., stress-induced and diffusionless). Consequently, the material would be harder at 1200 °C than at 1100 °C thanks to diffusion that would strengthen thermodynamically stable phases or grain-boundary structures. This alternative scenario for the LAB would not require volatiles. Instead, tectonic plates may slide on a layer in which the peridotite is constantly adjusting via a grain-boundary transformation.

Inspection Of Recombination Active Defects For Sige And Solar Cells

1996 ◽  
Vol 442 ◽  
Author(s):  
O.V. Astafiev ◽  
V.P. Kalinushkin ◽  
N.V. Abrosimov
Keyword(s):  
Solar Cells ◽  
Solar Cell ◽  
Light Scattering ◽  
Grain Boundary ◽  
Single Crystals ◽  
Defect Structure ◽  
Scattering Method ◽  
Recombination Activity ◽  
Cell Production ◽  
Materials Used

AbstractMapping Low Angle Light Scattering method (MLALS) is proposed to study defect structure in materials used for solar cell production. Several types of defects are observed in Czochralski Si1−xGex (0.022<x<0.047) single crystals. Recombination activity of these defects is investigated. The possibility of contactless visualisation of grain boundary recombination in polysilicon is also demonstrated.

Seed-Free Solid-State Growth of Large Lead-Free Piezoelectric Single Crystals: (Na1/2K1/2)NbO3

2015 ◽  
Vol 98 (10) ◽  
pp. 2988-2996 ◽  
Author(s):  
Minhong Jiang ◽  
Clive A. Randall ◽  
Hanzheng Guo ◽  
Guanghui Rao ◽  
Rong Tu ◽  
...  
Keyword(s):  
Solid State ◽  
Single Crystals ◽  
Lead Free ◽  
State Growth

High resolution triple resonance micro magic angle spinning NMR spectroscopy of nanoliter sample volumes

2016 ◽  
Vol 18 (6) ◽  
pp. 4902-4910 ◽  
Author(s):  
J. Ole Brauckmann ◽  
J. W. G. (Hans) Janssen ◽  
Arno P. M. Kentgens
Keyword(s):  
Solid State ◽  
Nmr Spectroscopy ◽  
High Resolution ◽  
Single Crystals ◽  
Solid State Nmr ◽  
Magic Angle Spinning ◽  
Magic Angle ◽  
Triple Resonance ◽  
Angle Spinning

To be able to study mass-limited samples and small single crystals, a triple resonance micro-magic angle spinning (μMAS) probehead for the application of high-resolution solid-state NMR of nanoliter samples was developed.

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