Stabilization of a face-centered-cubic Mn structure with the Ag lattice parameter

1997 ◽  
Vol 165 (1-3) ◽  
pp. 180-184 ◽  
Author(s):  
P. Schieffer ◽  
C. Krembel ◽  
M.C. Hanf ◽  
D. Bolmont ◽  
G. Gewinner
Keyword(s):  
Lattice Parameter ◽  
Face Centered Cubic ◽  
Face Centered

scholarly journals The Examination of Calcium ion Implanted Alumina with Energy Filtered Transmission Electron Microscopy

1997 ◽  
Vol 3 (S2) ◽  
pp. 413-414
Author(s):  
E.M. Hunt ◽  
J.M. Hampikian ◽  
N.D. Evans
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Pure Aluminum ◽  
Lattice Parameter ◽  
Face Centered Cubic ◽  
Ion Channeling ◽  
Transmission Electron ◽  
Knoop Microhardness ◽  
Aluminum Nanocrystals ◽  
Face Centered

Ion implantation can be used to alter the optical response of insulators through the formation of embedded nano-sized particles. Single crystal alumina has been implanted at ambient temperature with 50 keV Ca+ to a fluence of 5 x 1016 ions/cm2. Ion channeling, Knoop microhardness measurements, and transmission electron microscopy (TEM) indicate that the alumina surface layer was amorphized by the implant. TEM also revealed nano-sized crystals ≈7 - 8 nm in diameter as seen in Figure 1. These nanocrystals are randomly oriented, and exhibit a face-centered cubic structure (FCC) with a lattice parameter of 0.409 nm ± 0.002 nm. The similarity between this crystallography and that of pure aluminum (which is FCC with a lattice parameter of 0.404 nm) suggests that they are metallic aluminum nanocrystals with a slightly dilated lattice parameter, possibly due to the incorporation of a small amount of calcium.Energy-filtered transmission electron microscopy (EFTEM) provides an avenue by which to confirm the metallic nature of the aluminum involved in the nanocrystals.

Crystallographic Structure of Cobalt Films on CU (100)

1993 ◽  
Vol 313 ◽  
Author(s):  
O. Heckmann ◽  
H. Magnan ◽  
P. Le Fevre ◽  
D. Chandesris
Keyword(s):  
Normal Incidence ◽  
Grazing Incidence ◽  
Lattice Parameter ◽  
Crystallographic Structure ◽  
Face Centered Cubic ◽  
Fee Structure ◽  
The Face ◽  
The Mean ◽  
Face Centered ◽  
Hexagonal Closed Packed

ABSTRACTThe stable structure of cobalt is hexagonal closed packed (hep), but cobalt can be stabilized in the face centered cubic structure (fee) by epitaxy on Cu (100). These films are ferromagnetic with [110] in plane easy axis. The Magnetic anisotropies of these films strongly depend on their structure, and in particular to the possible deviation from the isotropie fee structure. We have studied these films by surface EXAF.S. By recording the spectra both in normal incidence and in grazing incidence we have shown that the Co/Cu (100) films have a face centered tetragonal structure: the mean nearest neighbour distance parallel to the surface is 2.55 Å (same value as in bulk copper) and the interlayer bonds length is 2.50 Å (same value as in bulk cobalt). We conclude that the films are in perfect epitaxy on copper (100) with a contraction of the lattice parameter perpendicular to the surface of 4%. A constant tetragonalization is observed for films of 2 to 15 Monolayers.

The Thermal Stability of a Single-Grain Mg-Zn-Y Icosahedral Quasicrystal

2000 ◽  
Vol 643 ◽  
Author(s):  
Z.P. Luo ◽  
Y.L. Tang ◽  
D.J. Miller ◽  
M.J. Kramer ◽  
I.R. Fisher ◽  
...  
Keyword(s):  
Golden Ratio ◽  
Lattice Parameter ◽  
Icosahedral Quasicrystal ◽  
Face Centered Cubic ◽  
Single Grain ◽  
Face Centered ◽  
The Stability ◽  
Mg Content ◽  
Thermal Stability Of

AbstractThe stability of the Mg-Zn-Y icosahedral quasicrystal (IQC) has been studied by long-term annealing of a single grain IQC in quartz tubes. Decomposition of the IQC was observed after annealing at high temperatures (T≥773 K) sealed in Ar. During the decomposition process, the quasilattice parameter aR was found to decrease, associated with a decrease in Mg content of the IQC phase as confirmed by quantitative x-ray energy dispersive spectroscopy analyses. In addition, a new cubic approximant has been found in the annealed samples. This cubic approximant has a face-centered cubic (fcc) structure with lattice parameter of a = 1.276 nm, which is about (1/τ) times smaller than that of the fcc W'-(MgZnY) with a = 2.05 nm reported previously (where τ is the golden ratio).

Evolution of the Transrotational Structure During Crystallization of Amorphous Ge2Sb2Te5 Thin Films

2009 ◽  
Vol 1160 ◽  
Author(s):  
Emanuele Rimini ◽  
Riccardo De Bastiani ◽  
Egidio Carria ◽  
Maria Grazia Grimaldi ◽  
Giuseppe Nicotra ◽  
...  
Keyword(s):  
Thin Films ◽  
Film Surface ◽  
Xrd Analysis ◽  
Lattice Parameter ◽  
Cubic Phase ◽  
Face Centered Cubic ◽  
Tem Analysis ◽  
The Face ◽  
Face Centered ◽  
Average Lattice

AbstractThe crystallization of amorphous Ge2Sb2Te5 thin films has been studied by X-ray diffraction (XRD) and transmission electron microscopy (TEM). The analysis has been performed on partially crystallized films, with a surface crystalline fraction (fS) ranging from 20% to 100%. XRD analysis indicates the presence, in the partially transformed layer, of grains with average lattice parameters higher than that of the equilibrium metastable cubic phase (from 6.06 Å at fS=20% to 6.01 Å at fS=100%). The amorphous to crystal transition, as shown by TEM analysis, occurs through the nucleation of face-centered-cubic crystal domains at the film surface. Local dimples appear in the crystallized areas, due to the higher atomic density of the crystal phase compared to the amorphous one. At the initial stage of the transformation, a fast bi-dimensional growth of such crystalline nucleus occurs by the generation of transrotational grains in which the lattice bending gives rise to an average lattice parameter significantly larger than that of the face-centered-cubic phase in good agreement with the XRD data. As the crystallized fraction increases above 80%, dimples and transrotational structures start to disappear and the lattice parameter approaches the bulk value.

Nano-Sized Cuboid-Shaped Phase in Mg–Nd–Y Alloy and its Behavior During Isothermal Aging

2016 ◽  
Vol 22 (6) ◽  
pp. 1244-1250 ◽  
Author(s):  
Jingxu Zheng ◽  
Zhongyuan Luo ◽  
Lida Tan ◽  
Bin Chen
Keyword(s):  
Isothermal Aging ◽  
Lattice Parameter ◽  
Dark Field ◽  
Atomic Scale ◽  
Face Centered Cubic ◽  
Transmission Electron ◽  
Scanning Transmission ◽  
Annular Dark Field ◽  
Face Centered ◽  
Image Position

AbstractIn the present study, nano-sized cuboid-shaped particles in Mg–Nd–Y are studied by means of Cs-corrected atomic-scale high-angle annular dark-field scanning transmission electron microscopy. The structure of the cuboid-shaped phase is identified to be yttrium (major component) and neodymium atoms in face-centered cubic arrangement without the participation of Mg. The lattice parameter a=5.15 Å. During isothermal aging at 225°C, Mg3(Nd,Y) precipitates adhere to surface (100) planes of the cuboid-shaped particles with the orientation relationship: $[100]_{{{\rm Mg}_{{\rm 3}} {\rm RE}}} \,/\,\,/\,[100]_{{{\rm Cuboid}}} $ and $[310]_{{{\rm Mg}_{{\rm 3}} {\rm RE}}} \,/\,\,/\,[012]_{{{\rm Cuboid}}} $ . The fully coherent interfaces between the precipitates and the cuboid-shaped phases are reconstructed and categorized into two types: $(400)_{{{\rm Mg}_{{\rm 3}} {\rm RE}}} $ interface and $(200)_{{{\rm Mg}_{{\rm 3}} {\rm RE}}} $ interface.

FACE-CENTERED CUBIC COBALT-RICH SOLID SOLUTIONS IN BINARY ALLOYS WITH ALUMINUM, GALLIUM, SILICON, GERMANIUM, AND TIN

1963 ◽  
Vol 41 (5) ◽  
pp. 758-761 ◽  
Author(s):  
Huey-Lin Luo ◽  
Pol Duwez
Keyword(s):  
Solid Solutions ◽  
Silicon Germanium ◽  
Single Phase ◽  
Lattice Parameter ◽  
Liquid Alloys ◽  
Face Centered Cubic ◽  
Equilibrium Conditions ◽  
Cooling Liquid ◽  
Face Centered ◽  
Straight Lines

By rapidly cooling liquid alloys, single-phase face-centered cubic cobalt-rich solid solutions have been obtained with up to 17.2 at.% aluminum, 18.2 at.% gallium, 13 at.% silicon, 17.4 at.% germanium, and 5 at.% tin. With the exception of silicon, these limits of solubility exceed those found under equilibrium conditions. The variation of lattice parameter with composition has been measured and the data can be fitted with straight lines for all solute elements except gallium, in which a change of slope is observed at 13.2 at.%.

Electrodeposition of Nanomodulated Ceramic Thin Films

1990 ◽  
Vol 180 ◽  
Author(s):  
Jay A. Switzer ◽  
Michael J. Shane ◽  
Richard J. Phillips
Keyword(s):  
Mixed Oxides ◽  
Ceramic Materials ◽  
Mean Free Path ◽  
Lattice Parameter ◽  
Face Centered Cubic ◽  
Individual Layer ◽  
Face Centered ◽  
Average Lattice ◽  
Quantum Optical ◽  
Electron Mean Free Path

ABSTRACTElectrochemistry can be used for the atomic-level architecture of ceramic materials. In this report, ceramic superlattices based on the TlaPbbOc/TldPbeOf system were electrodeposited with individual layer thicknesses as thin as 3nm. The superlattices were deposited from a single aqueous solution at room temperature, and the layer thicknesses were galvanostatically controlled. Substitution of Tl2O3 into PbO2 appears to stabilize a face-centered cubic structure with an average lattice parameter of 0.536nm. The lattice parameters for the T1aPbbOc. mixed oxides vary by less than 0.3% when the Pb/Tl ratio is varied from 0.84 to 7.3. Because the modulation wavelengths are of electron mean free path dimensions, this new class of degenerate semiconductor metal-oxide superlattices may show thickness-dependent quantum optical, electronic, or optoelectronic effects.

A Segregative MC Carbide in Centrifugal Casting High Speed Steel Roll

2010 ◽  
Vol 154-155 ◽  
pp. 269-272
Author(s):  
Yi Kun Luan ◽  
Nan Nan Song ◽  
Yun Long Bai ◽  
Xiu Hong Kang ◽  
Dian Zhong Li
Keyword(s):  
Chemical Composition ◽  
High Speed ◽  
Centrifugal Casting ◽  
High Speed Steel ◽  
Lattice Parameter ◽  
Face Centered Cubic ◽  
Metallic Elements ◽  
Rectangular Shape ◽  
Steel Roll ◽  
Face Centered

A novel segregative carbide was discovered during the manufacture of high speed steel roll. The carbide with rectangular shape is a type of MC carbide not yet reported in the open literature. It is a face centered cubic carbide with a lattice parameter a=0.414445 nm, very close to the VC carbide but with a different chemical composition. The M represents the metallic elements (at.%): 91.80 V, 3.17 Cr, 2.19 Fe and 2.83 Mo.

Effect of aging in hydrogen atmosphere on electrical conductivity of Cu–3at.%Ti alloy

2008 ◽  
Vol 23 (2) ◽  
pp. 473-477 ◽  
Author(s):  
Satoshi Semboshi ◽  
Toyohiko J. Konno
Keyword(s):  
Electrical Conductivity ◽  
Aging Time ◽  
Lattice Parameter ◽  
Hydrogen Atmosphere ◽  
Face Centered Cubic ◽  
Electrical Conductivities ◽  
The Face ◽  
Face Centered ◽  
Fcc Phase ◽  
Pure Cu

The electrical conductivities of Cu–3at.%Ti alloys aged at 773 K in a hydrogen atmosphere were investigated as a function of aging time. The electrical conductivity of the quenched alloy, 5.2% International Annealed Copper Standard (IACS), improved with aging time to 66% IACS after 48 h. This was mainly caused by the dilution of the Cu–Ti solid solution in the alloy, which is supported by the fact that the lattice parameter of the face-centered cubic (fcc) phase approaches that of pure Cu by aging in a hydrogen atmosphere.

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