Nucleation and growth process of sodalite and cancrinite from kaolinite-rich clay under low-temperature hydrothermal conditions

In the last decade and a half, thin film research, particularly research into problems associated with epitaxy, has developed from a simple empirical process of determining the conditions for epitaxy into a complex analytical and experimental study of the nucleation and growth process on the one hand and a technology of very great importance on the other. During this period the thin films group of the University of Chile has studied the epitaxy of metals on metal and insulating substrates. The development of the group, one of the first research groups in physics to be established in the country, has parallelled the increasing complexity of the field.The elaborate techniques and equipment now needed for research into thin films may be illustrated by considering the plant and facilities of this group as characteristic of a good system for the controlled deposition and study of thin films.

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Role of boundaries in the crystallization of amorphous films

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100105199 ◽

1988 ◽

Vol 46 ◽

pp. 626-627

Author(s):

D. A. Smith

Keyword(s):

Low Temperature ◽

Amorphous State ◽

Nucleation And Growth ◽

Amorphous Films ◽

Island Nucleation ◽

Surface Steps ◽

Transmission Electron ◽

Component Systems ◽

Temperature Deposition

The nucleation and growth processes which lead to the formation of a thin film are particularly amenable to investigation by transmission electron microscopy either in situ or subsequent to deposition. In situ studies have enabled the observation of island nucleation and growth, together with addition of atoms to surface steps. This paper is concerned with post-deposition crystallization of amorphous alloys. It will be argued that the processes occurring during low temperature deposition of one component systems are related but the evidence is mainly indirect. Amorphous films result when the deposition conditions such as low temperature or the presence of impurities (intentional or unintentional) preclude the atomic mobility necessary for crystallization. Representative examples of this behavior are CVD silicon grown below about 670°C, metalloids, such as antimony deposited at room temperature, binary alloys or compounds such as Cu-Ag or Cr O2, respectively. Elemental metals are not stable in the amorphous state.

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Formation and Structure of Thin Mo Layers and Mo-Ni Multilayers on Ni(001) by Molecular Beam Epitaxy

MRS Proceedings ◽

10.1557/proc-160-215 ◽

1989 ◽

Vol 160 ◽

Author(s):

Y.H. Lee ◽

R.P. Burns ◽

J.B. Posthill ◽

K.J. Bachmann

Keyword(s):

Thin Films ◽

High Temperature ◽

High Resolution ◽

Molecular Beam Epitaxy ◽

Low Temperature ◽

Molecular Beam ◽

Nucleation And Growth ◽

Multilayer Heterostructures ◽

Annealing Experiments ◽

Small Period

AbstractThe growth of Mo overtayers and Mo-Ni multilayers on single crystal Ni(001) substrates is described. The nucleation and growth processes of these thin films were analyzed by LEED, XPS, AES and SEM and High Resolution AES investigations without breaking vacuum. Growth of Mo-Ni multilayer heterostructures on Ni(001) with ≈20Å periodicity is possible at low temperature (≈200 °C). At high temperature (≈550 °C) the growth proceeds by the Volmer-Weber mechanism preventing the deposition of small period multilayers. Annealing experiments on ultra-thin (<20Å) Mo overiayers deposited at 200 °C show an onset of interdiffusion at ≈ 550°C coupled to the generation of a new surface periodicity.

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Synthesis and crystal structure of carbonate cancrinite Na8[AlSiO4]6CO3(H2O)3.4, grown under low-temperature hydrothermal conditions

Microporous and Mesoporous Materials ◽

10.1016/s1387-1811(99)00046-3 ◽

1999 ◽

Vol 30 (2-3) ◽

pp. 347-358 ◽

Cited By ~ 35

Author(s):

K. Hackbarth ◽

Th.M. Gesing ◽

M. Fechtelkord ◽

F. Stief ◽

J.-Ch. Buhl

Keyword(s):

Crystal Structure ◽

Low Temperature ◽

Hydrothermal Conditions ◽

Synthesis And Crystal Structure

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Nucleation and growth of N- and P-type microcrystals in low-temperature glow-discharge deposited silicon films

Journal of Non-Crystalline Solids ◽

10.1016/0022-3093(84)90294-1 ◽

1984 ◽

Vol 66 (1-2) ◽

pp. 31-37 ◽

Cited By ~ 10

Author(s):

P.E. Vanier ◽

J. Tafto ◽

G. Rajeswaran ◽

F.J. Kampas

Keyword(s):

Low Temperature ◽

Glow Discharge ◽

Nucleation And Growth ◽

Silicon Films ◽

P Type

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Nucleation and growth of Al2O3/metal composites by oxidation of aluminum alloys

Journal of Materials Research ◽

10.1557/jmr.1991.1964 ◽

1991 ◽

Vol 6 (9) ◽

pp. 1964-1981 ◽

Cited By ~ 79

Author(s):

O. Salas ◽

H. Ni ◽

V. Jayaram ◽

K.C. Vlach ◽

C.G. Levi ◽

...

Keyword(s):

Growth Process ◽

Nucleation And Growth ◽

Al Alloy ◽

Oxide Growth ◽

Spinel Layer ◽

Initial Oxidation ◽

Temperature Oxidation ◽

Continuous Formation ◽

Initial Event ◽

Al Composite

The nucleation and growth mechanisms during high temperature oxidation of liquid Al−3% Mg and Al−3% Mg−3% Si alloys were studied with the aim of enhancing our understanding of a new composite fabrication process. The typical oxidation sequence consists of an initial event of rapid but brief oxidation, followed by an incubation period of limited oxide growth after which bulk Al2O3/Al composite forms. A duplex oxide layer, MgO (upper) and MgAl2O4 (lower), forms on the alloy surface during initial oxidation and incubation. The spinel layer remains next to the liquid alloy during bulk oxide growth and is the eventual repository for most of the magnesium in the original alloy. Metal microchannels developed during incubation continuously supply alloy through the composite to the reaction interface. During the growth process, a layered structure exists at the upper extremity of the composite, consisting of MgO at the top surface, MgAl2O4 (probably discontinuous), Al alloy, and finally the bulk Al2O3 composite containing microchannels of the alloy. The bulk oxide growth mechanism appears to involve continuous formation and dissolution of the Mg-rich oxides at the surface, diffusion of oxygen through the underlying liquid metal, and epitaxial growth of Al2O3 on the existing composite body. The roles of Mg and Si in the composite growth process are discussed.

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Investigations of BaFe0.5Nb0.5O3 nano powders prepared by a low temperature aqueous synthesis and resulting ceramics

10.31219/osf.io/cwymu ◽

2019 ◽

Author(s):

Roberto Köferstein

Keyword(s):

Thermal Expansion ◽

Low Temperature ◽

Growth Process ◽

Optical Band Gap ◽

High Specific Surface Area ◽

Crystallite Growth ◽

Crystalline Powder ◽

Aqueous Synthesis ◽

Nano Crystalline ◽

Naoh Solution

A facile method to prepare nanoscaled BaFe0.5Nb0.5O3 via synthesis in boiling NaOH solution is describedherein. The nano-crystalline powder has a high specific surface area of 55 m2 g−1 and a crystallite sizeof 15 nm. The as-prepared powder does not show any significant crystallite growth up to 700 ◦C. Theactivation energy of the crystallite growth process was calculated as 590 kJ mol−1. Dense ceramics can beobtained either after sintering at 1200 ◦C for 1 h or after two-step sintering at 1000 ◦C for 10 h. The averagegrain sizes of ceramic bodies can be tuned between 0.23 µm and 12 µm. The thermal expansion coefficientwas determined as 11.4(3)·10−6 K−1. The optical band gap varies between 2.90(5) and 2.63(3) eV. Magneticmeasurements gave a Néel temperature of 20 K. Depending on the sintering regime, the ceramic samplesreach permittivity values between 2800 and 137,000 at RT and 1 kHz.

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Optical Investigation of 3C-SiC Hetero-Epitaxial Layers Grown by Sublimation Epitaxy under Gas Atmosphere

Materials Science Forum ◽

10.4028/www.scientific.net/msf.778-780.243 ◽

2014 ◽

Vol 778-780 ◽

pp. 243-246

Author(s):

P. Kwasnicki ◽

V. Jokubavicius ◽

J.W. Sun ◽

H. Peyre ◽

R. Yakimova ◽

...

Keyword(s):

Low Temperature ◽

Growth Process ◽

Epitaxial Layers ◽

Optical Investigation ◽

Defect Sites ◽

Vacuum Atmosphere ◽

Gas Atmosphere ◽

Low Temperature Photoluminescence

We investigated three 3C-SiC samples grown on 6H SiC substrate by sublimation epitaxy under gas atmosphere. We focus on the low temperature photoluminescence and Raman measurements to show that compare to a growth process under vacuum atmosphere, the gas atmosphere favor the incorporation of impurities at already existing and/or newly created defect sites.

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