Orientation control of vacuum deposited epitaxial metal films by applying external stress

1978 ◽  
Vol 36 (1) ◽  
pp. 152-153
Author(s):  
S. Maruyama ◽  
K. Yamamoto
Keyword(s):  
Rock Salt ◽  
Room Temperature ◽  
Gold Film ◽  
Metal Films ◽  
Film Plane ◽  
Epitaxial Films ◽  
External Stress ◽  
Flash Method ◽  
Ordered Structure ◽  
Copper Gold

The orientation of vacuum deposited, epitaxial metal films was controlled, by applying external stress, on copper gold ordered alloy, and on gold manganese ordered alloy.Ordered tetragonal or quasi-tetragonal epitaxial films such as CuAuI and gold manganese α″ have the mixed orientation of the shorter axis normal and parallel to the film plane,in the usual deposition in vacuum, i.e., (i)when the copper was deposited immediately after the gold was deposited, on cleaved surface of rock salt and homogenized, as is shown in Fig.la., or (ii)when it is formed by flash method (the two constituent atoms are deposited simultaneously), as shown in Fig.2a. This is very troublesome for the analysis or interpretation of the ordered structure of alloys. The author controlled the orientation so that the shorter axis is overall normal to the film plane in both CuAuI and gold manganese α″ by the following way. An epitaxial gold film held at room temperature for one night was rapidly heated to 350°C (at the rate of 15°C per minute), then copper or manganese was deposited onto it at that temperature, and homogenized

Effects of Ionized Cluster Beam Bombardment on Epitaxial Metal Film Deposition on Silicon Substrates

1988 ◽  
Vol 128 ◽  
Author(s):  
Isao Yamada
Keyword(s):  
Room Temperature ◽  
Lattice Mismatch ◽  
Ion Beam ◽  
Substrate Surface ◽  
Metal Films ◽  
Epitaxial Films ◽  
Film Structure ◽  
Film Deposition ◽  
Cluster Beam ◽  
Tem Analysis

ABSTRACTThe effects of ion beam bombardment during ionized cluster beam (ICB) deposition of metal films on Si(111) and Si(100) substrates have been discussed. In the case of Al deposition, films have been epitaxially deposited on Si(lll) and Si(100) substrates at near room temperature. On Si(111) substrates, nearly perfect Al single crystal films could be formed. On Si(100) substrates, Al bicrystals have been grown epitaxially. A remarkable fact concerning these results is that the epitaxial films could be formed at nearly room temperature and on a large lattice mismatch (25%) substrate surface. Atomic resolution TEM analysis suggests that the epitaxy of Al occurs not only on Si surfaces but also at Al/Al grain boundaries. These epitaxial films exhibit extremely high thermal stability and long electromigration life time. To understand the deposition features and film characteristics, the effects of ICB bombardment on the film growth at the initial stage of the deposition and the resultant film structure have been studied. The results show that the role of very low energy ion bombardment is especially important in forming epitaxial metal films. Depositions of Au and Cu on Si substrates have also been made to understand whether ICB deposition may improve the characteristics of other metal films. Preliminary results of these film depositions are also obtained.

Thermal Strain Study of Almost Lattice-Matched Epitaxial InuGa1-uAs1-vP1-v Films on InP(100) Substrates

1989 ◽  
Vol 160 ◽  
Author(s):  
G. Bai ◽  
M-A. Nicolet ◽  
S.-J. Kim ◽  
R.G. Sobers ◽  
J.W. Lee ◽  
...  
Keyword(s):  
Room Temperature ◽  
Epitaxial Film ◽  
Lattice Mismatch ◽  
Thermal Strain ◽  
Growth Direction ◽  
Epitaxial Films ◽  
Double Crystal ◽  
X Ray ◽  
Lattice Matched ◽  
Coherent Interfaces

AbstractSingle layers of ~ 0.5µm thick InuGa1-uAs1-vPv (0.52 < u < 0.63 and 0.03 < v < 0.16) were grown epitaxially on InP(100) substrates by liquid phase epitaxy at ~ 630°C. The compositions of the films were chosen to yield a constant banndgap of ~ 0.8 eV (λ = 1.55 µm) at room temperature. The lattice mismatch at room temperature between the epitaxial film and the substrate varies from - 4 × 10-3 to + 4 × 10-3. The strain in the films was characterized in air by x-ray double crystal diffractometry with a controllable heating stage from 23°C to ~ 700°C. All the samples have an almost coherent interfaces from 23°C to about ~ 330°C with the lattice mismatch accomodated mainly by the tetragonal distortion of the epitaxial films. In this temperature range, the x-ray strain in the growth direction increases linearly with temperature at a rate of (2.0 ± 0.4) × 10-6/°C and the strain state of the films is reversible. Once the samples are heated above ~ 300°C, a significant irreversible deterioration of the epitaxial films sets in.

On the Structure of Some Pentaerythritol-Related Molecular Crystals with Pseudotetrahedral Molecular Structure. Ordered Structure of 2,2-Bis(bromomethyl)-1,3-propanediol and Orientationally Disordered Structure of 2-Chloromethyl-2-methyl-1,3-dichloropropane; 35Cl NQR

1996 ◽  
Vol 51 (5-6) ◽  
pp. 777-785 ◽  
Author(s):  
Shi-qi Dou ◽  
Hartmut Fuess ◽  
Roman Strauß ◽  
Alarich Weiss
Keyword(s):  
Room Temperature ◽  
Molecular Crystals ◽  
Monoclinic Space Group ◽  
Heating Cycle ◽  
Ordered Structure ◽  
Intermolecular Hydrogen Bonds ◽  
Oh Groups ◽  
Disordered Structure ◽  
35Cl Nqr ◽  
Plastic Phase

Abstract C(CH2Cl)3(CH3), melting point Tm = 291.3 K, shows in the DTA/DSC experiment a phase tran-sition from an orientationally disordered plastic phase I into an ordered phase II at TI ⃗ II = 235.9 K. From 77 K up to TII ⃗ I the 35Cl NQR spectrum is a triplet with (ν in MHz, T=77 K) ν1 = 34.213, ν2 = 34.183, ν3 = 33.786. The 35Cl NQR fade-out temperature Tf = 247 K coincides with TII ⃗ I found from the DSC experiment. The plastic phase of 2-chloromethyl-2-methyl-l,3-propanediol is cubic bcc, Im3m, Z = 2 and the lattice constant increases linearly 755 pm at 235 K to 768 pm at 283 K. In the heating cycle we found (ΔH in kJ/mol): ΔHII ⃗ I = 12.0, ΔSm/R = 1.0. The compound belongs to the group of plastic molecules formed by ellipsoid like distorted tetrahedra and is derived by substitution from methane. The crystal structure of 2,2-bis(bromomethyl)-1,3-propanediol was determined. DTA-DSC show that an orientationally disordered plastic phase does not exist. At room temperature C(CH2Br)2(CH2OH)2 crystallizes monoclinic, space group Cc, Z = 4, a = 628.2 pm, 6 = 2015.5 pm, c = 659.6 pm, β = 94.27°. The molecules interact by intermolecular hydrogen bonds between the OH-groups and by van der Waals forces Br…Br.

Structural Characterization of Thin Metal Overlayers by X-ray Photoelectron and Auger-Electron Forward Scattering

1986 ◽  
Vol 83 ◽  
Author(s):  
W. F. Egelhoff
Keyword(s):  
Ultrathin Films ◽  
Surface Segregation ◽  
Metal Films ◽  
Epitaxial Films ◽  
Forward Scattering ◽  
Crystalline Lattice ◽  
Auger Electrons ◽  
X Ray ◽  
Metal Overlayers

ABSTRACTForward scattering of XPS and Auger electrons by atoms in a crystalline lattice produce beams of enhanced intensity radiating out from the surface at angles corresponding to the internuclear axes present in the top few atomic layers. This effect has been applied to analyze the mechanism of surface segregation in ultrathin metal films, to analyze the interdiffusion at the interfaces of ultrathin films, and to assess the effects of substrate contamination on the growth of epitaxial films. The systems studied in this work are Cu, Ni, and Co on Ni(100), however the purpose of this work is not to investigate these particular systems but to use them to illustrate the capabilities of forward scattering.

Mechanical Properties and Ordered Structure of Bacterial Poly(3-Hydroxybutyrate-Co-3-Hydroxyhexanoate) Fibers Stretched after Isothermal Crystallization near Tg

2011 ◽  
Vol 284-286 ◽  
pp. 1774-1777 ◽  
Author(s):  
Chang Kun Ding ◽  
Bo Wen Cheng ◽  
Qiong Wu
Keyword(s):  
Isothermal Crystallization ◽  
Melt Spinning ◽  
Room Temperature ◽  
Low Molecular Weight ◽  
Ordered Structure ◽  
X Ray Diffraction ◽  
Recombinant Bacteria ◽  
X Ray ◽  
Flexible Fibers ◽  
One Step

Biodegradable fibers of poly(3-hydroxybutyrate-co-3-hydroxyhexanoate) (PHBHHx) were prepared by melt spinning, followed by one-step-drawing with small crystal nuclei grown after isothermal crystallization near the glass transition temperature (Tg) and annealing at room temperature under tension. This new drawing technique is a very attractive method for obtaining flexible fibers from low-molecular-weight biopolyesters produced by recombinant bacteria. The ordered structure of PHBHHx fibers was investigated by tensile measurement, scanning electron microscopy, and wide-angle X-ray diffraction (WAXD). The tensile strength of 10 times one-step-drawn fiber after isothermal crystallization increased to 100 MPa. The WAXD profiles of PHBHHx fibers showed sharp reflections corresponding to highly oriented α-form (21helix conformation) crystal.

Recent Developments in Thermodynamic Theory of Ferroelectric Thin Films

2005 ◽  
Vol 902 ◽  
Author(s):  
Nikolay Pertsev
Keyword(s):  
Thermodynamic Formalism ◽  
Film Plane ◽  
Epitaxial Films ◽  
Thermodynamic Theory ◽  
Theoretical Studies ◽  
Structure Property ◽  
Ferroelectric Films ◽  
Structure Property Relationships ◽  
Recent Developments ◽  
Further Development

AbstractThe nonlinear thermodynamic theory of epitaxial ferroelectric films has predicted several important strain-induced phenomena, which have been already observed experimentally. This justifies further development of this theory aiming at the better understanding of the structure/property relationships in thin-film ferroelectrics. To that end, a number of new theoretical studies have been performed recently. First, the thermodynamic formalism has been extended to epitaxial films grown on dissimilar substrates inducing anisotropic strains and a shear deformation in the film plane. Second, the polarization states and dielectric properties were calculated for polydomain Pb(Zr1-xTix)O3 films deposited on cubic substrates. Third, the effect of depolarizing field on the physical properties of strained single-domain films sandwiched between continuous electrodes was described. The results of these studies will be discussed in this paper.

Modulation of magnetism induced by external stress in ultra-thin metal films on a flexible substrate

2016 ◽  
Vol 2016 (0) ◽  
pp. J2210201
Author(s):  
Shinya OTA ◽  
Ryo ASAI ◽  
Do Bang ◽  
Hiroyuki Awano ◽  
Takahiro KOZEKI ◽  
...  
Keyword(s):  
Flexible Substrate ◽  
Metal Films ◽  
External Stress ◽  
Thin Metal ◽  
Thin Metal Films
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