scholarly journals Pressure-Induced Dimerization of C60 at Room Temperature as Revealed by an In Situ Spectroscopy Study Using an Infrared Laser

Crystals ◽  
2020 ◽  
Vol 10 (3) ◽  
pp. 182 ◽  
Author(s):  
Bing Li ◽  
Jinbo Zhang ◽  
Zhipeng Yan ◽  
Meina Feng ◽  
Zhenhai Yu ◽  
...  
Keyword(s):  
Room Temperature ◽  
Infrared Laser ◽  
Face Centered Cubic ◽  
X Ray Diffraction ◽  
Simple Cubic ◽  
Excitation Laser ◽  
Face Centered ◽  
830 Nm Laser ◽  
Structure Evaluation

Using in situ high-pressure Raman spectroscopy and X-ray diffraction, the polymerization and structure evaluation of C60 were studied up to 16 GPa at room temperature. The use of an 830 nm laser successfully eliminated the photo-polymerization of C60, which has interfered with the pressure effect in previous studies when a laser with a shorter wavelength was used as excitation. It was found that face-centered cubic (fcc) structured C60 transformed into simple cubic (sc) C60 due to the hint of free rotation for the C60 at 0.3 GPa. The pressure-induced dimerization of C60 was found to occur at about 3.2 GPa at room temperature. Our results suggest the benefit and importance of the choice of the infrared laser as the excitation laser.

scholarly journals In Situ Synthesis of Polyaniline Based Ceramic Wastes Composites: Dielectric and Electrical Properties

2021 ◽  
Author(s):  
M. Sohail ◽  
Adnan Shahzad ◽  
Mian Gul Sayed ◽  
Ihsan Ullah ◽  
M. Omer ◽  
...  
Keyword(s):  
Composite Material ◽  
High Frequency ◽  
Room Temperature ◽  
In Situ Synthesis ◽  
Face Centered Cubic ◽  
Dielectric Analysis ◽  
Photovoltaic Detectors ◽  
Pani Composite ◽  
Face Centered

Abstract In the present study, ceramic wastes collected from the premises of industrial zone in Peshawar, KP Pakistan were investigated. An effort has been made to recycle and use the ceramic wastes as fillers in polymeric composites. The negative cost ceramic wastes were purified and activated thermally. The elemental composition and pellets of the wastes were investigated through SEM/EDX analysis. Waste/Polyaniline (PANI) composite was synthesized via in-situ free radical polymerization technique. SEM of the composites showed the uniform distribution of fillers particles in the PANI matrix. XRD studies confirmed that the prepared composite material had a face- centered cubic geometry with distinct preferential orientations. Dielectric analysis showed that the materials exhibit active performance at high frequency regions (3MHz to 3GHz) at room temperature. The results show decrease in dielectric losses and capacitance (1.6 pF) at high frequency regions. AC conductivity of the composite has been increased up to 37.95 Scm-1. This revealed the effect of PANI on the ceramic wastes while increasing its conductance performance. This suggests that the composite material can be investigated for use in photovoltaic detectors, electro-responsive capacitors and power applications.

Grain Growth and Mechanical Properties of Nanograined Bulk Fe-25Ni Alloy

2005 ◽  
Vol 475-479 ◽  
pp. 3459-3462
Author(s):  
Hong Bin Wang ◽  
Xiao Yu Wang ◽  
J.H. Zhang ◽  
T.Y. Hsu
Keyword(s):  
Mechanical Properties ◽  
Grain Growth ◽  
Coarse Grained ◽  
Growth Exponent ◽  
Face Centered Cubic ◽  
X Ray Diffraction ◽  
Ni Alloy ◽  
Face Centered ◽  
Fcc Phase

The grain growth and mechanical properties of nanograined bulk Fe-25at%Ni alloy prepared by an inert gas condensation and in-situ warm consolidation technique were investigated. About 43% high temperature face-centered-cubic (FCC) phase and 57% low temperature body-centered-cubic (BCC) phase were observed in the sample at room temperature, which was significantly different from that of the corresponding conventional coarse-grained alloy. The in-situ X-ray diffraction results show that the start and the finish temperature of BCC to FCC phase transformation are 450°C and 600°C, respectively. The isothermal grain growth exponent n from t k D D n n ¢ = − 1 0 1 for nanograined single FCC phase Fe-25at%Ni alloy is 0.38 at 750 °C . The mechanical properties changing with the grain size were studied by means of microindentation test.

In situ high-temperature X-ray diffraction characterization of silver sulfide, Ag2S

2011 ◽  
Vol 26 (2) ◽  
pp. 114-118 ◽  
Author(s):  
Thomas Blanton ◽  
Scott Misture ◽  
Narasimharao Dontula ◽  
Swavek Zdzieszynski
Keyword(s):  
High Temperature ◽  
Structure Refinement ◽  
Silver Sulfide ◽  
Rietveld Analysis ◽  
Face Centered Cubic ◽  
X Ray Diffraction ◽  
X Ray ◽  
Face Centered ◽  
Fcc Phase

Silver sulfide, Ag2S, is most commonly known as the tarnish that forms on silver surfaces due to the exposure of silver to hydrogen sulfide. The mineral acanthite is a monoclinic crystalline form of Ag2S that is stable to 176°C. Upon heating above 176°C, there is a phase conversion to a body-centered cubic (bcc) form referred to as argentite. Further heating above 586°C results in conversion of the bcc phase to a face-centered cubic (fcc) phase polymorph. Both high-temperature cubic phases are solid-state silver ion conductors. In situ high-temperature X-ray diffraction was used to better understand the polymorphs of Ag2S on heating. The existing powder diffraction file (PDF) entries for the high-temperature fcc polymorph are of questionable reliability, prompting a full Rietveld structure refinement of the bcc and fcc polymorphs. Rietveld analysis was useful to show that the silver atoms are largely disordered and can only be described by unreasonably large isotropic displacement parameters or split site models.

scholarly journals The Rolling Texture of Cu3Au

Texture ◽  
1974 ◽  
Vol 1 (3) ◽  
pp. 143-150 ◽  
Author(s):  
R. A. Vandermeer ◽  
J. C. Ogle
Keyword(s):  
Room Temperature ◽  
Pure Copper ◽  
Rolling Texture ◽  
Wire Drawing ◽  
Face Centered Cubic ◽  
Long Range Order ◽  
X Ray Diffraction ◽  
X Ray ◽  
Partial Dislocations ◽  
Face Centered

The rolling texture of Cu3Au has been investigated by X-ray diffraction. At room temperature, independently of the degree of long-range order, Cu3Au developed a mixed or “hybrid” texture; it consisted of elements of each of the prototype face-centered cubic textures characterized by pure copper and 70/30 brass. However, on rolling at 77 K the alloy in the disordered state was significantly more “brass-like” than when it was fully ordered. This result may be explained by a stacking fault energy texture reversal analogous to that observed in wire drawing at low SFE. The lack of twinning (or other deformation mechanism such as slip by partial dislocations) in the ordered alloy could be responsible for this reversal.

scholarly journals Cation Distribution in Natural Chromites from Oman

1996 ◽  
Vol 1 (1) ◽  
pp. 55
Author(s):  
Z. Al-Alawi ◽  
A.M. Gismelseed ◽  
A.A. Yousif ◽  
M.A. Worthing ◽  
H.H. Sutherland ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Room Temperature ◽  
Face Centered Cubic ◽  
X Ray Diffraction ◽  
Atomic Concentration ◽  
X Ray ◽  
Diffraction Patterns ◽  
Face Centered ◽  
Mössbauer Analysis ◽  
Scanning Electron

Two specimens or natural chromite from the Oman ophiolite were studied using Mossbauer Spectroscopy (MS), X-ray Diffraction (XRD). and Scanning Electron Microscopy (SEM). The diffraction patterns obtained at room temperature showed that the two specimens have a face-centered cubic spinal structure. Their Mossbauer spectra at 295 K. 160 K and 78 K have been fitted to three doublets. assigned to two Fe 2+ at the tetrahedral (A1+,A2) sites and one Fe1+ at the octahedral (B) site. The ferrous-ferric ratio obtained from the Mossbauer analysis together with the atomic concentration derived from the microprobe data are used to derive the chemical formulae for the two specimens. The data also supports also supports  a model of ordered caution distribution in the specimens examined.

scholarly journals Structural, Thermal, Optical, Electrical, and Adhesive Characteristics of FePdB Thin Films

2015 ◽  
Vol 2015 ◽  
pp. 1-5
Author(s):  
Yuan-Tsung Chen
Keyword(s):  
Thin Films ◽  
Activation Energy ◽  
Room Temperature ◽  
Face Centered Cubic ◽  
X Ray Diffraction ◽  
Dc Magnetron Sputtering ◽  
Adhesive Properties ◽  
X Ray ◽  
Face Centered ◽  
Xrd Patterns

To study the structural, thermal, electrical, optical, and adhesive properties of magnetic FePdB thin films, 25–200-Å-thick Fe40Pd40B20and Fe60Pd20B20films were deposited on a glass substrate by direct current (DC) magnetron sputtering at room temperature (RT). X-ray diffraction (XRD) patterns indicated that the 25–75-Å-thick Fe40Pd40B20and Fe60Pd20B20films were amorphous, whereas the 100–200-Å-thick Fe40Pd40B20and Fe60Pd20B20films were crystalline, with a face-centered cubic (FCC) FePd (111) textured structure. The activation energy of the Fe40Pd40B20and Fe60Pd20B20thin films decreased as thickness was increased. The 25-Å-thick Fe40Pd40B20film exhibited the highest resistivity, whereas the 200-Å-thick Fe60Pd20B20film exhibited the lowest resistivity. Increasing the thickness and crystallization reduced transmission. The Fe40Pd40B20thin films exhibited higher surface energy and stronger adhesion than did Fe60Pd20B20thin films.

Hydrogen-induced structural transformation of AuCu nanoalloys probed by synchrotron X-ray diffraction techniques

Nanoscale ◽  
2014 ◽  
Vol 6 (8) ◽  
pp. 4067-4071 ◽  
Author(s):  
M. Yamauchi ◽  
K. Okubo ◽  
T. Tsukuda ◽  
K. Kato ◽  
M. Takata ◽  
...  
Keyword(s):  
Structural Transformation ◽  
Hydrogen Atmosphere ◽  
Face Centered Cubic ◽  
X Ray Diffraction ◽  
X Ray ◽  
Face Centered

In situ X-ray diffraction measurements reveal that the transformation of a AuCu nanoalloy from a face-centered-cubic to an L10 structure is accelerated under a hydrogen atmosphere.

In Situ X-Ray Diffraction Analysis of Face-Centered Cubic Metals Deformed at Room and Cryogenic Temperatures

2019 ◽  
Vol 28 (8) ◽  
pp. 4658-4666
Author(s):  
Marcel Tadashi Izumi ◽  
John Jairo Hoyos Quintero ◽  
Maicon Rogerio Crivoi ◽  
Milene Yumi Maeda ◽  
Ricardo Sanson Namur ◽  
...  
Keyword(s):  
Diffraction Analysis ◽  
Face Centered Cubic ◽  
Cryogenic Temperatures ◽  
X Ray Diffraction ◽  
X Ray ◽  
Cubic Metals ◽  
Face Centered

New designs of hydrophobic and mesostructured Ultra Low k materials with isolated mesopores

2011 ◽  
Vol 1335 ◽  
Author(s):  
Anthony Grunenwald ◽  
André Ayral ◽  
Pierre Antoine Albouy ◽  
Vincent Rouessac ◽  
David Jauffres ◽  
...  
Keyword(s):  
Grazing Incidence ◽  
Face Centered Cubic ◽  
X Ray Diffraction ◽  
X Ray ◽  
In Situ Xrd ◽  
X Ray Scattering ◽  
Face Centered ◽  
Film Porosity ◽  
Low K

ABSTRACTIn this work, hydrophobic mesostructured organosilica thin films, exhibiting isolated mesopores (~ 7 nm), have been successfully deposited by spin-coating using different polystyrene-block-polyethylene oxide copolymers (PS-b-PEO) as structure-directing agents and methyltriethoxysilane (MTES) as organosilica precursor. Different ordered mesostructures (Face Centered Cubic, 2D or 3D Hexagonal and Body Centered Cubic) can be achieved by controlling different synthesis parameters. X-Ray Diffraction (XRD) and Grazing Incidence Small Angle X-Ray Scattering (GISAXS) techniques were used to investigate the mesostructure evolution through thermal and UV treatments. Swelling and shrinkage were evidenced by in-situ XRD and X-Ray Reflectivity measurements during the thermal removal of the meso-templates. Infrared spectroscopy and 29Si NMR were additionally used to investigate the microstructure evolution. The film porosity was estimated thanks to Ellipsometry Porosimetry (EP). Correlation between mechanical properties through nanoindentation measurements and the mesostructure ordering is discussed as well as assessments of the dielectric constant k by mercury contact probe.

Effects of thermal annealing on the texture of La0.67Sr0.33MnO3 thin films

2001 ◽  
Vol 16 (7) ◽  
pp. 1887-1889 ◽  
Author(s):  
Lamartine Meda ◽  
LaQuita Kennon ◽  
Cristiane Bacaltchuk ◽  
Hamid Garmestani ◽  
Klaus H. Dahmen
Keyword(s):  
Thin Films ◽  
Vapor Deposition ◽  
Metalorganic Chemical Vapor Deposition ◽  
Chemical Vapor ◽  
Face Centered Cubic ◽  
X Ray Diffraction ◽  
X Ray ◽  
Simple Cubic ◽  
Heat Treated ◽  
Face Centered

Thin films of La0.67Sr0.33MnO3 (LSMO) were prepared at 670 °C on LaAlO3 (LAO) and SrTiO3 (STO) substrates by liquid-delivery metalorganic chemical vapor deposition. X-ray diffraction analysis 2¸/¸ and pole figure scans showed that the films are epitaxial with (001)LSMO//(001)LAO and (001)LSMO//(001)STO. The crystal structure of LSMO/LAO was indexed as face-centered cubic with a double cell and LSMO/STO as simple cubic. Electron microscopy revealed square facets and elongated grain features. Films heat-treated between 700 and 800 °C on LAO resulted in a structural change, while those on STO showed an increase in texture.

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