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.

Investigation of Heat Treated Electrodeposited CoNiFe on Microstructure and Hardness

2015 ◽  
Vol 1113 ◽  
pp. 56-61
Author(s):  
Nor Azrina Resali ◽  
Koay Mei Hyie ◽  
M.N. Berhan ◽  
C.M. Mardziah
Keyword(s):  
Heat Treatment ◽  
Heat Treatment Temperature ◽  
Treatment Temperature ◽  
Crystallographic Structure ◽  
Face Centered Cubic ◽  
Heat Treated ◽  
Hardness Property ◽  
Finishing Process ◽  
The Face ◽  
Face Centered

In this research, heat treatment is the final finishing process applied on nanocrystalline CoNiFe to improve microstructure for good hardness property. Nanocrystalline CoNiFe has been synthesized using the electrodeposition method. This study investigated the effect of heat treatment at 500°C, 600°C, 700°C and 800°C on electrodeposited nanocrystalline CoNiFe. The heat treatment process was performed in the tube furnace with flowing Argon gas. By changing the heat treatment temperature, physical properties such as phase and crystallographic structure, surface morphology, grain size and hardness of nanocrystalline CoNiFe was studied. The nanocrystalline CoNiFe phase revealed the Face Centered Cubic (FCC) and Body Centered Cubic (BCC) crystal structure. FESEM micrographs showed that the grain sizes of the coatings were in the range of 78.76 nm to 132 nm. Dendrite shape was found in the microstructure of nanocrystalline CoNiFe. The nanocrystalline CoNiFe prepared in heat treatment temperature of 700°C, achieved the highest hardness of 449 HVN. The surface roughness of nanocrystalline CoNiFe heated at 700°C was found to be smaller than other temperatures.

Comparison of Trapping Sites of Anthracene in Hexagonal and Cubic Argon Matrices: a Molecular Dynamics Study

2000 ◽  
Vol 214 (6) ◽  
Author(s):  
D. Horinek ◽  
B. Dick
Keyword(s):  
Molecular Dynamics ◽  
Random Search ◽  
Face Centered Cubic ◽  
Host Crystal ◽  
Unique Site ◽  
The Face ◽  
Face Centered ◽  
Argon Matrices ◽  
Hexagonal Closed Packed ◽  
Trapping Sites

Geometries and energies for possible trapping sites of anthracene in hexagonal closed packed (hcp) argon matrices have been calculated and compared to corresponding trapping sites calculated for the face centered cubic fcc argon host. The random search method (RSM) has been applied which combines statistical and molecular dynamics (MD) components in the generation of initial geometries and their relaxation. A total of 1322 runs yielded 12 unique site structures. In none of them the anthracene is located in the {111}-plane of the host crystal, in contrast to the situation found for the fcc host structure.

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.

scholarly journals Neighborhood M-Polynomial of Crystallographic Structures

2020 ◽  
Vol 11 (2) ◽  
pp. 9372-9381
Keyword(s):  
Cuprous Oxide ◽  
Topological Indices ◽  
Crystallographic Structure ◽  
Face Centered Cubic ◽  
Mathematical Chemistry ◽  
Fcc Lattice ◽  
The Face ◽  
Crystallographic Structures ◽  
Face Centered

The mathematical chemistry is wealthy, having tools such as polynomials and functions that can predict the properties of compounds. The M-polynomial is one of them which yields degree-based topological indices. In this work, we define the neighborhood M-polynomial to obtain neighborhood degree-based topological indices. Further, we compute some neighborhood degree-based topological indices of the face-centered cubic (fcc) lattice and the crystallographic structure of cuprous oxide (〖Cu〗_2 O) using the neighborhood M-polynomial approach. Also, the results are shown graphically.

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.

scholarly journals Characterization of crystal structure and precipitation crystallography of a new MgxAl2−xGd phase in an Mg97Al1Gd2alloy

2016 ◽  
Vol 49 (4) ◽  
pp. 1177-1181 ◽  
Author(s):  
X.-F. Gu ◽  
T. Furuhara
Keyword(s):  
Crystal Structure ◽  
Lattice Parameter ◽  
Face Centered Cubic ◽  
Laves Phases ◽  
Transmission Electron ◽  
Scanning Transmission ◽  
The Matrix ◽  
The Face ◽  
Face Centered

The composition, crystal structure and precipitation crystallography of a newly found precipitate are characterized by Cs-corrected scanning transmission electron microscopy. The composition of the plate-like precipitate could be expressed as MgxAl2−xGd (x= 0.38), and its crystal structure is the same as the face-centered cubic type Laves phases Mg2Gd and Al2Gd, with a lattice parameter of 7.92 Å (space group No. 227, Fd\overline 3m). The orientation relationship between the matrix and precipitate is found to be (0001)m//(111)pand [10\overline 10]m//[1\overline 10]p, and the habit plane is parallel to the (0001)m//(111)pplane. In addition, this preferred crystallography of phase transformation is well explained on the basis of the atomic matching at the interface.

A Correlation of Phase Change with Stress Corrosion Fracture in Alpha-Brass

CORROSION ◽  
1972 ◽  
Vol 28 (11) ◽  
pp. 424-426
Author(s):  
W. D. SYLWESTROWICZ
Keyword(s):  
Phase Change ◽  
Stress Corrosion ◽  
Hexagonal Structure ◽  
Face Centered Cubic ◽  
Corrosion Fracture ◽  
Fee Structure ◽  
The Face ◽  
Face Centered ◽  
Alpha Brass ◽  
Fracture Specimens

Abstract Prestrained α-brass specimens, containing 1.9% lead, were exposed to stress corrosion at 30 and 90 C (86 and 194 F). It was found that at least 10% of prestraining was needed to fracture specimens in stress corrosion tests. It was also observed that in specimens strained more than 10% the face centered cubic (fee) structure of α-brass was transformed, inside of the specimen, to the hexagonal structure. It is postulated, that transformation of the fee structure to the hexagonal structural causes susceptibility of α-brass to the stress corrosion fracture.

A Study of Structure and Thermal Parameters of Biomedical Used Ni20Pd80 Alloy

2013 ◽  
Vol 380-384 ◽  
pp. 4303-4306
Author(s):  
Ya Jing Zhang ◽  
Li Xin Li
Keyword(s):  
Thermal Expansion ◽  
Debye Temperature ◽  
Coefficient Of Thermal Expansion ◽  
Linear Thermal Expansion ◽  
Lattice Parameter ◽  
Thermal Parameters ◽  
Face Centered Cubic ◽  
X Ray Diffraction ◽  
The Mean ◽  
Face Centered

The structure and thermal parameters of biomedical used Ni20Pd80 alloy were studied using X-ray diffraction (XRD) technique. The diffraction experiments performed in the temperature range of 308-1100 K revealed that the alloy forms a face centered cubic (fcc) A1-type structure. The temperature dependence of the lattice parameters was investigated using the Bragg line displacement method shows that the lattice parameter increases with the increase of temperature. The mean linear thermal expansion (MLTE (%)), coefficient of thermal expansion (CTE) α, the characteristic Debye temperature (ΘD) and mean square amplitudes of vibration were determined from the XRD data. The value of Debye temperature was found to be 253 K. It was found that temperature factor was independent of the static displacements.

A study of interface sliding at F.C.C.-B.C.C. boundaries in a Cu-Zn alloy

1978 ◽  
Vol 36 (1) ◽  
pp. 422-423
Author(s):  
F. Monchoux ◽  
A. Rocher ◽  
J.L. Martin
Keyword(s):  
Face Centered Cubic ◽  
Creep Tests ◽  
High Voltage Electron Microscopy ◽  
Diffusion Treatment ◽  
Voltage Electron ◽  
The Face ◽  
Face Centered ◽  
Interface Sliding ◽  
Zn Alloy ◽  
Made In

Interphase sliding is an important phenomenon of high temperature plasticity. In order to study the microstructural changes associated with it, as well as its influence on the strain rate dependence on stress and temperature, plane boundaries were obtained by welding together two polycrystals of Cu-Zn alloys having the face centered cubic and body centered cubic structures respectively following the procedure described in (1). These specimens were then deformed in shear along the interface on a creep machine (2) at the same temperature as that of the diffusion treatment so as to avoid any precipitation. The present paper reports observations by conventional and high voltage electron microscopy of the microstructure of both phases, in the vicinity of the phase boundary, after different creep tests corresponding to various deformation conditions.Foils were cut by spark machining out of the bulk samples, 0.2 mm thick. They were then electropolished down to 0.1 mm, after which a hole with thin edges was made in an area including the boundary

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