Stress Driven Instability in Non-Hydrostatically Stressed Crystals and its Role in the Problems of Crystalline Thin Films

1991 ◽  
Vol 239 ◽  
Author(s):  
Michael A. Grinfeld
Keyword(s):  
Thin Films ◽  
Surface Tension ◽  
Crystal Growth ◽  
Solid Phase ◽  
Elastic Solids ◽  
Phase Boundaries ◽  
Crystalline Film ◽  
Physical Mechanisms ◽  
Epitaxial Crystal Growth

ABSTRACTIt was demonstrated in [1] that, in the absence of surface tension aflat boundary of non-hydrostatically stressed elastic solids is always unstable with respect to “mass rearrangement”. The physical mechanisms of the rearrangement can be different, for instance, a)melting-freezing or vaporization-sublimation processes at liquid-solid or vapor-solid phase boundaries, b»surface diffusion of particles along free or interfacial boundaries, b)adsorption-desorbtion of the atoms in epitaxial crystal growth, etc… We discuss the role of this instability in the problems of epitaxy and, in particular, the opportunities delivered by this instability for explanation of the recently discovered phenomena of the dislocation-free Stranski-Krastanow pattern of growth [2]. These phenomena cannot be interpreted in the framework of traditional viewpoints since, according to the classical theory, the Stranski-Krastanow pattern is a result of proliferation of the misfit dislocation appearing on the interface “crystalline film-substratum” [3].

Crystal Growth of β-FeSi2 Thin Film on (100), (110) and (111) Plane of Si and Yittria-stabilized Zirconia Substrates

2006 ◽  
Vol 980 ◽  
Author(s):  
Kensuke Akiyama ◽  
Satoru Kaneko ◽  
Takanori Kiguchi ◽  
Takashi Suemasu ◽  
Takeshi Kimura ◽  
...  
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Crystal Growth ◽  
Magnetron Sputtering ◽  
Iron Silicide ◽  
Rf Magnetron Sputtering ◽  
Single Element ◽  
Stabilized Zirconia ◽  
Crystalline Film ◽  
Anions And Cations

AbstractIron silicide thin films were prepared on silicon (Si) and yittria-stabilized zirconia (YSZ) substrates using RF magnetron sputtering and evaporation methods. Epitaxial b-FeSi2 thin films were grown on (100) and (111) planes of Si and YSZ substrates, while noncrystallized films were deposited on (110) plane of both Si and YSZ substrates. The epitaxial relationships between the b-FeSi2 and YSZ were the same as those between b-FeSi2 and Si, in the case of (100) and (111) planes. It is possible that epitaxial b-FeSi2 film can be grown when substrates and b-FeSi2 surfaces consist of either a single element or only cations, while the crystalline film was not shown when either substrate or b-FeSi2 surface consists of a mixture of anions and cations or iron and silicon.

The Universal Instability of the Separation Boundary Between a Non-Hydrostatically Stressed Elastic Crystal and its Melt

1991 ◽  
Vol 237 ◽  
Author(s):  
Michael A. Grinfeld
Keyword(s):  
Surface Tension ◽  
Stress Field ◽  
Materials Science ◽  
Solid Phase ◽  
Instability Mechanism ◽  
Liquid Media ◽  
Separation Boundary ◽  
Crystalline Films ◽  
Neutral Equilibrium

ABSTRACTIn the absence of surface tension and external force fields, the equilibrium between a hydrostatically stressed crystal and its melt is neutral with respect to the perturbations associated with particle transfer from one region of the boundary into another. However, under the action of arbitrary small nonhydrostatic components of the stress field in the elastic crystal, the neutral equilibrium is transformed to an unstable equilibrium [1]. This instability is very general in nature; for example, for it to be seen the liquid media need only to be able to dissolve the solid phase or in some way to assist the transport of particles along the crystal's surface. In contrast, the surface tension, roughly speaking, stabilizes the shape of the interphase boundary but it cannot suppress the instability generated by the nonhydrostatic components of the stress field in the region of sufficiently long perturbations. Until now the basic instability mechanism discussed here seems to have escaped the attention of theorists. This mechanism allows one to look in a completely new way at a broad range of phenomena. We discuss tentative manifestations and role of this instability in low temperature physics, in materials science, in theory of crystal growth, and, in particular, in theory of epitaxy and of the Stranski-Krastanow pattern of growth of thin crystalline films.

scholarly journals Role of anti-phase boundaries in the formation of magnetic domains in magnetite thin films

2021 ◽  
Author(s):  
Roberto Moreno ◽  
Sarah Jenkins ◽  
Aleksandar Skeparovski ◽  
Zlatko Nedelkovski ◽  
Alexander Gerber ◽  
...  
Keyword(s):  
Thin Films ◽  
Magnetic Domains ◽  
Phase Boundaries

Growth and Characterization of Poly-SiGe Prepared by Reactive Thermal CVD

2004 ◽  
Vol 808 ◽  
Author(s):  
Jianjun Zhang ◽  
Kousaku Shimizu ◽  
Jun-ichi Hanna
Keyword(s):  
Thin Films ◽  
Activation Energy ◽  
Growth Rate ◽  
Crystal Growth ◽  
Electrical Properties ◽  
Flow Rate ◽  
Amorphous Film ◽  
Thermal Cvd

ABSTRACTWe have prepared poly-Si1-xGex thin films with different germanium contents (Ge=5%∼40%) by reactive thermal CVD. In this study, the Ge content was controlled by varying the source gases GeF4 flow rate at a fixed Si2H6 flow rate. The effects of GeF4 flow rate on growth rate, film crystallinity, and electrical properties were investigated. The films were always polycrystalline when GeF4 was introduced even in a small amount, while only amorphous film deposited without GeF4. With an increase in GeF4 flow rate, Ge content and conductivity of the films increased and its activation energy decreased. When GeF4 flow rate over a certain value, the growth rate decrease and finally no film could be deposited. These behaviors are discussed in relation with a role of GeF4 for the crystal growth at a low temperature.

Surfactant-Mediated Si/Ge Epitaxial Crystal Growth

1996 ◽  
Vol 448 ◽  
Author(s):  
Eunja Kim ◽  
Chan Wuk OH ◽  
Young Hee Lee
Keyword(s):  
Molecular Dynamics ◽  
Crystal Growth ◽  
Ab Initio ◽  
Crucial Role ◽  
Flat Surface ◽  
Exchange Process ◽  
Epitaxial Crystal Growth

AbstractWe investigate the kinetic role of a surfactant in the epitaxial Si/Ge crystal growth using ab initio molecular dynamics approach. We examine the previously suggested dimer-exchange mechanisms and find that kinetics plays a crucial role in determining the exchange process. We further find that the diffusion of adatoms on an island in the presence of a surfactant is quite different from the dimer-exchange process on a flat surface.

Role of glycopeptides and pepddes in inhibition of crystallization of water in polar fishes

1984 ◽  
Vol 304 (1121) ◽  
pp. 575-588 ◽  
Keyword(s):  
Crystal Growth ◽  
Basal Plane ◽  
Solid Phase ◽  
Freezing Point ◽  
Body Fluids ◽  
Molecular Masses ◽  
Polar Oceans

In the ice-laden polar oceans, water temperatures of — 2 °C are common. This temperature is 1.1 °C below the equilibrium freezing point ( — 0.9 °C) of the fishes’ body fluids. Avoidance of freezing in these environments has been linked to the presence of unusual blood peptides and glycopeptides. These molecules have molecular masses ranging from 2.5 to 20 kDa and are viewed as having antifreeze properties because they lower the freezing point of water by a non-colligative process. A 2% solution of antifreeze has a freezing point of — 1.2 °C and ice formed in their presence melts at — 0.02 °C. Measurements of antifreeze concentrations in ice indicate that these molecules, unlike other proteins of similar size and conformation, are incorporated into the solid phase during freezing and adsorb to it. Adsorption of the antifreezes to ice appears to inhibit growth along the preferred axes ( a -axes) by raising the curvature of the growth steps on the basal plane. At temperatures below — 1.2 °C, crystal growth occurs in the form of long spicules whose axes are parallel to the c -axis, the non-preferred axis of growth.

Influence of solvent additive on the chemical and electronic environment of wide bandgap perovskite thin films

2018 ◽  
Vol 6 (44) ◽  
pp. 12052-12061 ◽  
Author(s):  
Shivam Singh ◽  
Dinesh Kabra
Keyword(s):  
Thin Films ◽  
Crystal Growth ◽  
Wide Bandgap ◽  
Electronic Environment ◽  
Solvent Additive ◽  
Kinetics Of ◽  
Insight Into ◽  
Kinetics Of Crystal Growth ◽  
Influence Of Solvent

We provide in-depth insight into the role of 1,8-diiodooctane (DIO) as a solvent additive in wide bandgap CH3NH3PbBr3 (MAPbBr3) films which results in altering the kinetics of crystal growth.

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