Structural characterization of damage in Si(100) produced by MeV Si+ ion implantation and annealing

Buried amorphous layers were produced by implantation of MeV Si+ ions in silicon single crystal at room temperature and liquid nitrogen temperature. The damage is characterized structurally both in the as-implanted condition and after post-implantation furnace annealing. Growth of the amorphous layer during room temperature implantation is found to occur by a layer-by-layer mechanism with relatively sharp interfacial transition regions. A wide region ahead of the buried amorphous region extending to the surface is observed to be free of any extended defects. Recrystallization of the damaged region during thermal annealing occurs by solid-phase epitaxial growth at both interfaces. A lower growth velocity is found at the upper interface, which is attributed to a higher hairpin dislocation density grown-in at this interface. Results of irradiation at liquid nitrogen temperature, on the other hand, show that nucleation and growth of the amorphous damage occurs over a wide region and is not confined to the interfacial region. This results in a very diffuse upper interface composed of a mixture of amorphous and crystalline phases. Substantial reordering is observed in this mixed-phase region after 400°C annealing, even though this temperature is too low for normal interfacial solid-phase epitaxial growth. Cross-sectional transmission electron microscopy, as well as Rutherford backscattering spectroscopy, were used in this study.

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Infrared Spectra of the Alkali Metal Cyanides in the Solid State

Applied Spectroscopy ◽

10.1366/000370273774333821 ◽

1973 ◽

Vol 27 (2) ◽

pp. 93-94 ◽

Cited By ~ 5

Author(s):

Zakya K. Ismail ◽

Robert H. Hauge ◽

John L. Margrave

Keyword(s):

Solid State ◽

Alkali Metal ◽

Liquid Nitrogen ◽

Infrared Spectra ◽

Room Temperature ◽

Solid Phase ◽

Liquid Nitrogen Temperature ◽

Metal Cyanides ◽

Sodium And Potassium

The infrared spectra of lithium isocyanide and of sodium and potassium cyanides in the solid phase were examined over the range 4000 to 140 cm−1 at room temperature. A study of the effect of cooling the solids to liquid nitrogen temperature has been carried out.

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Ion Implantation and Annealing of Oxides

MRS Proceedings ◽

10.1557/proc-74-357 ◽

1986 ◽

Vol 74 ◽

Cited By ~ 18

Author(s):

C. W. White ◽

L. A. Boatner ◽

P. S. Sklad ◽

C. J. Mchargue ◽

S. J. Pennycook ◽

...

Keyword(s):

Ion Implantation ◽

Liquid Nitrogen ◽

Amorphous Phase ◽

Room Temperature ◽

Solid Phase ◽

Liquid Nitrogen Temperature ◽

Pure Material ◽

Near Surface ◽

Implantation Damage ◽

Crystalline Oxides

AbstractIon implantation damage and annealing results are presented for a number of crystalline oxides. In A12 O3, the amorphous phase produced by ion bombardment of the pure material first crystallizes in the (crystalline) γ phase. This is followed by the transformation of γ-Al2 O3 to α-A12O3 at a well defined interface. The activation energy for the growth of α alumina from γ is 3.6 eV/atom. In CaTiO3, the implantation-induced amorphous phase transforms to the crystalline phase by solid-phase epitaxy (SPE). ZnO is observed to remain crystalline even after high implantation doses at liquid nitrogen temperatures. The near surface of KTaO3 is transformed to a polycrystalline state after implantation at room temperature or liquid nitrogen temperature.

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Cryogenic Interlaminar Properties of PBO Fiber/Epoxy Composites

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.391-392.1445 ◽

2011 ◽

Vol 391-392 ◽

pp. 1445-1449

Author(s):

Chun Hua Zhang ◽

Shi Lin Luan ◽

Xiu Song Qian ◽

Bao Hua Sun ◽

Wen Sheng Zhang

Keyword(s):

Liquid Nitrogen ◽

Room Temperature ◽

Liquid Nitrogen Temperature ◽

Epoxy Composites ◽

Bending Test ◽

Test Results ◽

Sem Images ◽

Three Point Bending ◽

Pbo Fiber ◽

Interlaminar Shear

The influences of low temperature on the interlaminar properties for PBO fiber/epoxy composites have been studied at liquid nitrogen temperature (77 K) in terms of three point bending test. Results showed that the interlaminar shear strength at 77 K were significantly higher than those at room temperature (RT). For the analysis of the test results, the tensile behaviors of epoxy resin at both room temperature and liquid nitrogen temperature were investigated. The interface between fiber and matrix was observed using SEM images.

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Research on DC Breakdown and Flashover Characteristics of PI with Different Temperature

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.709.11 ◽

2016 ◽

Vol 709 ◽

pp. 11-14

Author(s):

Tian Ye Niu ◽

Jia Xin Wu ◽

Ying Wen Li ◽

Dong Sheng Xu ◽

Lu Li ◽

...

Keyword(s):

Liquid Nitrogen ◽

Room Temperature ◽

Rapid Development ◽

Liquid Nitrogen Temperature ◽

Power Equipment ◽

Electrical Characteristics ◽

Cryogenic Temperatures ◽

Insulating Materials ◽

Dielectric Performance ◽

Working Performance

The electrical characteristics of insulating materials play a key role on the working performance and operation reliability of power equipment. With the rapid development of superconducting technology in recent years,the working temperature of high temperature superconducting power equipment can be controlled around the liquid nitrogen temperature. Due to its excellent dielectric performance and mechanical properties, polyimide have been widely used in power equipment at room temperature. However, polyimide, as a kind of cryogenic insulating materials, is rarely reported at present. Therefore, the study of the insulating characteristics of polyimide at the cryogenic temperatures is of great significance. The DC breakdown property and flashover performance of polyimide are tested around room temperature (300K) and liquid nitrogen temperature (78K). The results show that temperature has some effects on the DC breakdown property and flashover performance of polyimide.

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Application of interference fits on cylindrical monochromator crystals to overcome clamping and cooling deformations

Journal of Synchrotron Radiation ◽

10.1107/s1600577519001061 ◽

2019 ◽

Vol 26 (2) ◽

pp. 382-385

Author(s):

Joshua Stimson ◽

Michael Ward ◽

John Sutter ◽

Sofia Diaz-Moreno ◽

Simon Alcock ◽

...

Keyword(s):

Heat Exchanger ◽

Liquid Nitrogen ◽

Room Temperature ◽

Silicon Crystal ◽

Liquid Nitrogen Temperature ◽

Cryogenic Cooling ◽

Element Analysis ◽

Thermal Interface ◽

Macro Scale ◽

Order Of Magnitude

In order to provide adequate cryogenic cooling of both existing and next-generation crystal monochromators, a new approach to produce an optimum thermal interface between the first crystal and its copper heat exchanger is proposed. This will ensure that the increased heat load deposited by higher X-ray powers can be properly dissipated. Utilizing a cylindrical silicon crystal, a tubular copper heat exchanger and by exploiting the differing thermal and mechanical properties of the two, a very good thermal interface was achieved at liquid-nitrogen temperatures. The surface flatness of the diffracting plane at one end of the cylindrical crystal was measured at room temperature while unconstrained. The crystal was then placed into the copper heat exchanger, a slide fit at room temperature, and then cooled to liquid-nitrogen temperature. At −200°C the slide fit became an interference fit. This room-temperature `loose' fit was modelled using finite-element analysis to obtain the desired fit at cryogenic temperatures by prescribing the fit at room temperature. Under these conditions, the diffraction surface was measured for distortion due to thermal and mechanical clamping forces. The total deformation was measured to be 30 nm, an order of magnitude improvement over deformation caused by cooling alone with the original side-clamped design this concept method is set to replace. This new methodology also has the advantage that it is repeatable and does not require macro-scale tools to acquire a nanometre-accuracy mounting.

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Study of Electrical Properties of Ge-Nanocrystalline Films Deposited by Cluster-Beam Evaporation Technique

MRS Proceedings ◽

10.1557/proc-536-551 ◽

1998 ◽

Vol 536 ◽

Cited By ~ 2

Author(s):

Souri Banedjee ◽

H. Ono ◽

S. Nozaki ◽

H. Morisaki

Keyword(s):

Electrical Properties ◽

Liquid Nitrogen ◽

Coulomb Blockade ◽

Room Temperature ◽

Liquid Nitrogen Temperature ◽

Cluster Beam ◽

Nanocrystalline Films ◽

Current Voltage ◽

Evaporation Technique

AbstractRoom temperature current-voltage (I-V) characteristics were studied across the thickness of the Ge nanocrystalline films, prepared by the cluster beam evaporation technique. The films thus prepared are deposited either at room temperature (Ge-RT) or at liquid nitrogen temperature (Ge-LNT). Ge-LNT nanofilm is subjected to oxidation while Ge-RT did not get oxidized. Steps were observed in the I-V characteristics of the thin Ge- LNT samples suggesting the Coulomb Blockade effect.

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Surfactant Mediated Epitaxial Growth of Co on Au(111) Surface

MRS Proceedings ◽

10.1557/proc-749-w5.6 ◽

2002 ◽

Vol 749 ◽

Author(s):

Masao Kamiko ◽

Sang-Mun Oh ◽

Hiroaki Chihaya ◽

Hiroyuki Mizuno ◽

Junhua Xu ◽

...

Keyword(s):

Epitaxial Growth ◽

Layer Thickness ◽

Room Temperature ◽

Surface Segregation ◽

Growth Behavior ◽

Layer By Layer ◽

Heteroepitaxial Growth ◽

Suitable Amount

ABSTRACTWe have chosen Bi as the surfactant atom in the heteroepitaxial growth of Co on Au(111). It was found that Bi induces layer-by-layer (LBL) growth at room temperature. With pre-deposition of 0.2 ∼ 0.8Å Bi on Au(111) prior to the evaporation of Co, more long-lasting RHEED intensity oscillations were observed and this implies that it induces the LBL growth of Co film. The result of the dependence of the growth behavior as a function of Bi layer thickness suggests that there is a suitable amount of Bi surfactant layer that induces the smoother LBL growth. A surface segregation of Bi was found at the top of surface and acts as a surfactant by promoting the interlayer transport.

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Effect of Rolling Temperature on Microstructure and Mechanical Properties of Cryorolled Al-Mg-Si Alloy Reinforced with 3wt% TiB2 In Situ Composite

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.584.556 ◽

2012 ◽

Vol 584 ◽

pp. 556-560 ◽

Cited By ~ 11

Author(s):

B. Gopi ◽

N. Naga Krishna ◽

K. Sivaprasad ◽

K. Venkateswarlu

Keyword(s):

Mechanical Properties ◽

Liquid Nitrogen ◽

Room Temperature ◽

True Strain ◽

Liquid Nitrogen Temperature ◽

Tensile Tests ◽

Rolling Temperature ◽

Rolled Sample ◽

Peak Broadening

The present work investigates the effect of rolling temperature on the mechanical properties and microstructural evolution of an Al-Mg-Si alloy with 3wt% TiB2 in-situ composite that was fabricated by stir casting route. The composite was rolled to a true strain of ≈0.7 at three different temperatures viz; room temperature (RT), liquid propanol (LP) and liquid nitrogen (LN) temperatures. Tensile tests revealed that the samples rolled at liquid nitrogen temperature exhibited improved properties compared to the samples rolled at other two temperatures. A tensile strength and ductility of 291 MPa and 8% respectively were exhibited by the liquid nitrogen rolled sample. The strength is observed to be ≈12% higher and ductility is ≈60% more when compared to the room temperature rolled sample. X ray diffraction peaks indicated that rolled samples exhibited considerable increase in peak broadening compared to the unrolled one, which is attributed to the increase of the lattice strain due to distortion and the decrease in grain size of the material. The enhanced mechanical properties of the liquid nitrogen rolled samples were attributed to the combined effect of grain refinement and accumulation of higher dislocation density.

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Chemically disordered Ni3Al synthesized by high vacuum evaporation

Journal of Materials Research ◽

10.1557/jmr.1991.2019 ◽

1991 ◽

Vol 6 (10) ◽

pp. 2019-2021 ◽

Cited By ~ 50

Author(s):

S.R. Harris ◽

D.H. Pearson ◽

C.M. Garland ◽

B. Fultz

Keyword(s):

Liquid Nitrogen ◽

Room Temperature ◽

Single Phase ◽

High Vacuum ◽

Liquid Nitrogen Temperature ◽

Vacuum Evaporation ◽

Scanning Calorimetry ◽

X Ray ◽

Transmission Electron ◽

Average Grain Size

Films of chemically disordered fcc Ni3Al were synthesized by the vacuum evaporation of Ni3Al onto room temperature and liquid nitrogen temperature substrates. X-ray diffractometry and transmission electron microscopy showed the material to be single phase with an average grain size of about 4 nm. The formation of the equilibrium L12 ordered phase occurred simultaneously with grain growth at temperatures above 350°C. Differential scanning calorimetry provided ordering enthalpies of 7 kJ/mole and 9 kJ/mole for material evaporated onto room temperature and liquid nitrogen temperature substrates, respectively.

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