Charge transfer associated with lithium insertion in Mo1−yNbyS2 layered compounds

1984 ◽  
Vol 62 (1) ◽  
pp. 10-14 ◽  
Author(s):  
M. A. Py ◽  
R. R. Haering
Keyword(s):  
Voltage Drop ◽  
Structural Disorder ◽  
Host Lattice ◽  
Layered Compounds ◽  
Electrochemical Cells ◽  
X Ray Diffraction ◽  
Electronic Density ◽  
X Ray ◽  
Critical Composition ◽  
Trigonal Prismatic

The Mo1−yNbyS2 layered compounds form solid solutions. The coordination of the Mo and Nb atoms by S atoms is trigonal prismatic over the entire range of composition, 0 ≤ y ≤ 1. The [Formula: see text] band, separated from the other d-bands by a bandgap of the order of 1 eV, contains y empty states per formula unit. For y ≤ 0.6, Li/LixMo1−yNbyS2 electrochemical cells reveal a sharp voltage drop of V(x) at a critical composition x which is correlated to y by [Formula: see text]. This result clearly establishes the transfer of one electron per intercalated lithium (x ≤ 0.6) to the [Formula: see text] band of the host.Electrochemical cells, made with samples whose X-ray diffraction spectra suggest the presence of structural disorder in the host lattice, show a less abrupt voltage drop near xc, in qualitative agreement with the influence of disorder on the electronic density-of-states distribution N(E) near a band edge. The origin of the voltage drop observed for LixMo0.2Nb0.8S2 is not fully established.

Structural Properties Of Co/Re Superlattices

1991 ◽  
Vol 238 ◽  
Author(s):  
Y. Huai ◽  
R. W. Cochrane ◽  
Y. Shi ◽  
H. E. Fischer ◽  
M. Sutton
Keyword(s):  
Structural Disorder ◽  
Multilayer Films ◽  
Film Plane ◽  
X Ray Diffraction ◽  
X Ray ◽  
Bilayer Films ◽  
Out Of Plane ◽  
Reflectivity Data ◽  
Sharp Interfaces ◽  
Good Agreement

ABSTRACTThe structures of equal-thickness Co/Re multilayer films and several Co/Re bilayer films have been investigated by X-ray diffraction at low and high angles. Analysis of low-angle reflectivity data from bilayer films indicates that interfacial intermixing is limited to three monolayers and that the two interfacial configurations are different. The high-angle X-ray diffraction data show that multilayer films have coherent interfaces and a highly textured structure with hep [002] orientations normal to the film plane for periods 21 Å ≤ Λ ≤220 Å. Detailed structures have been determined by fitting the X-ray spectra to calculated ones using a trapezoidal model. The results indicate that samples with 42 Å≤ Λ ≤220 Å have relatively sharp interfaces, in good agreement with the bilayer results. In addition, an out-of-plane expansion of the Co (002) layer is observed in samples with large Λ and results from structural disorder leading to a reduced atomic density. For Λ <21 Å the interfaces arise from the rougher surfaces of the deposited layers.

Gallium-containing Heusler phases ScRh2Ga, ScPd2Ga, TmRh2Ga and LuRh2Ga – magnetic and solid state NMR-spectroscopic characterization

2017 ◽  
Vol 72 (8) ◽  
pp. 609-615
Author(s):  
Lukas Heletta ◽  
Stefan Seidel ◽  
Christopher Benndorf ◽  
Hellmut Eckert ◽  
Rainer Pöttgen
Keyword(s):  
Solid State ◽  
Solid State Nmr ◽  
Spectroscopic Characterization ◽  
Structural Disorder ◽  
X Ray Diffraction ◽  
Temperature Dependent ◽  
Phase Purity ◽  
X Ray ◽  
Arc Melting ◽  
Pauli Paramagnetism

AbstractThe gallium-containing Heusler phases ScRh2Ga, ScPd2Ga, TmRh2Ga and LuRh2Ga have been synthesized by arc-melting of the elements followed by different annealing sequences to improve phase purity. The samples have been studied by powder X-ray diffraction. The structures of Lu0.97Rh2Ga1.03 (Fm3̅m, a=632.94(5) pm, wR2=0.0590, 46 F2 values, seven variables) and Sc0.88Rh2Ga1.12 (a=618.91(4) pm, wR2=0.0284, 44 F2 values, six variables) have been refined from single crystal X-ray diffractometer data. Both gallides show structural disorder through Lu/Ga and Sc/Ga mixing. Temperature dependent magnetic susceptibility measurements showed Pauli paramagnetism for ScRh2Ga, ScPd2Ga, and LuRh2Ga and Curie-Weiss paramagnetism for TmRh2Ga. 45Sc and 71Ga solid state MAS NMR spectroscopic investigations of the Sc containing compounds confirmed the site mixing effects typically observed for Heusler phases. The data indicate that the effect of mixed Sc/Ga occupancy is significantly stronger in ScRh2Ga than in ScPd2Ga.

Effects of Indium Incorporation on the Optical Properties of ZnO Films

2006 ◽  
Vol 11-12 ◽  
pp. 159-162 ◽  
Author(s):  
Yong Ge Cao ◽  
Lei Miao ◽  
Sakae Tanemura ◽  
Yasuhiko Hayashi ◽  
Masaki Tanemura
Keyword(s):  
Optical Transmission ◽  
Full Width Half Maximum ◽  
Structural Disorder ◽  
Band Gaps ◽  
Zno Films ◽  
Photoluminescence Spectra ◽  
X Ray Diffraction ◽  
X Ray ◽  
Optical Band Gaps ◽  
Xrd Patterns

Transparent indium-doped ZnO (IZO) films with low In content (<6at%) were fabricated through radio-frequency (rf) helicon magnetron sputtering. Formation of In-Zn-O solid solution was confirmed by X-ray diffraction (XRD) patterns. Incorporation of indium into ZnO films enhances the optical transmission in the visible wavelength. The optical band-gaps slightly increase from 3.25eV (ZnO) to 3.28eV (In0.04Zn0.96O) and to 3.30eV (In0.06Zn0.94O) due to Burstain-Moss effect. The Urbach tail parameter E0, which is believed to be a function of structural disorder, increases from 79meV (ZnO), to 146meV (In0.04Zn0.96O), and to 173meV (In0.06Zn0.94O), which is consistent with increase of Full-Width Half-Maximum (FWHM) in corresponding XRD patterns. Decreasing in crystal quality with increasing indium concentration is also confirmed by photoluminescence spectra.

scholarly journals Bi3+ and Eu3+ Activated Luminescent Behaviors in Non-Stoichiometric LaO0.65F1.7 Structure

Materials ◽  
2020 ◽  
Vol 13 (10) ◽  
pp. 2326
Author(s):  
Sungjun Yang ◽  
Sangmoon Park
Keyword(s):  
Optical Materials ◽  
Emission Spectra ◽  
Lattice Energy ◽  
Host Lattice ◽  
X Ray Diffraction ◽  
Unit Cell Parameters ◽  
X Ray ◽  
Cell Parameters ◽  
Diffraction Patterns ◽  
Cation Sites

Optical materials composed of La1-p-qBipEuqO0.65F1.7 (p = 0.001–0.05, q = 0–0.1) were prepared via a solid-state reaction using La(Bi,Eu)2O3 and NH4F precursors at 1050 °C for two hours. X-ray diffraction patterns of the phosphors were obtained permitting the calculation of unit-cell parameters. The two La3+ cation sites were clearly distinguished by exploiting the photoluminescence excitation and emission spectra through Bi3+ and Eu3+ transitions in the non-stoichiometric host lattice. Energy transfer from Bi3+ to Eu3+ upon excitation with 286 nm radiation and its mechanism in the Bi3+- and Eu3+-doped host structures is discussed. The desired Commission Internationale de l’Eclairage values, including emissions in blue-green, white, and red wavelength regions, were obtained from the Bi3+- and Eu3+-doped LaO0.65F1.7 phosphors.

scholarly journals Structural and dynamic aspects related to oligomerization of apo SOD1 and its mutants

2009 ◽  
Vol 106 (17) ◽  
pp. 6980-6985 ◽  
Author(s):  
Lucia Banci ◽  
Ivano Bertini ◽  
Mirela Boca ◽  
Vito Calderone ◽  
Francesca Cantini ◽  
...  
Keyword(s):  
Solvent Accessibility ◽  
Structural Disorder ◽  
Free Form ◽  
X Ray Diffraction ◽  
X Ray ◽  
Conformational Variability ◽  
Metal Free ◽  
Loop Regions ◽  
Lateral Sclerosis ◽  
Apo State

The structural and dynamical properties of the metal-free form of WT human superoxide dismutase 1 (SOD1) and its familial amyotrophic lateral sclerosis (fALS)-related mutants, T54R and I113T, were characterized both in solution, through NMR, and in the crystal, through X-ray diffraction. We found that all 3 X-ray structures show significant structural disorder in 2 loop regions that are, at variance, well defined in the fully-metalated structures. Interestingly, the apo state crystallizes only at low temperatures, whereas all 3 proteins in the metalated form crystallize at any temperature, suggesting that crystallization selects one of the most stable conformations among the manifold adopted by the apo form in solution. Indeed, NMR experiments show that the protein in solution is highly disordered, sampling a large range of conformations. The large conformational variability of the apo state allows the free reduced cysteine Cys-6 to become highly solvent accessible in solution, whereas it is essentially buried in the metalated state and the crystal structures. Such solvent accessibility, together with that of Cys-111, accounts for the tendency to oligomerization of the metal-free state. The present results suggest that the investigation of the solution state coupled with that of the crystal state can provide major insights into SOD1 pathway toward oligomerization in relation to fALS.

Scanning Tunneling Microscopy Imaging of Defects in Layered Compounds

1990 ◽  
Vol 209 ◽  
Author(s):  
G. P. E. M. Van Bakell ◽  
J. Th. M. De Hosson ◽  
T. Hibma
Keyword(s):  
Scanning Tunneling Microscopy ◽  
Structural Features ◽  
Layered Compounds ◽  
Scanning Tunneling ◽  
X Ray Diffraction ◽  
Tunneling Microscopy ◽  
Microscopy Imaging ◽  
X Ray ◽  
Sample Orientation ◽  
Stm Images

ABSTRACTStructural features of TiS2 were studied by scanning tunneling microscopy (STM) and single-crystal X-ray diffraction was applied as a complementary technique. STM images in air and at room temperature revealed, beside the trigonal symmetry of the lattice, several new features having this symmetry as well. We conclude that these features not only are to be described by structural defect phenomena which affect octahedral sites in the 1T-CdI2 structure but tetrahedral sites as well. Sample orientation determination by X-ray diffraction provides a unique relation between feature types and sites. A model is proposed in which displaced Ti atoms account for the observed features.

X-ray diffraction study of lattice parameters for layered compounds MxTaS2(M=Tl or In)

1995 ◽  
Vol 7 (24) ◽  
pp. 4625-4628 ◽  
Author(s):  
T Takeda ◽  
S Yokozeki ◽  
K Yamamoto ◽  
K Ohshima
Keyword(s):  
Diffraction Study ◽  
Lattice Parameters ◽  
Layered Compounds ◽  
X Ray Diffraction ◽  
X Ray

scholarly journals Enantioselective assembly of multi-layer 3D chirality

2019 ◽  
Vol 7 (3) ◽  
pp. 588-599 ◽  
Author(s):  
Guanzhao Wu ◽  
Yangxue Liu ◽  
Zhen Yang ◽  
Tao Jiang ◽  
Nandakumar Katakam ◽  
...  
Keyword(s):  
Bottom Layer ◽  
Layered Compounds ◽  
Optoelectronic Materials ◽  
X Ray Diffraction ◽  
Aromatic Rings ◽  
X Ray ◽  
Strong Luminescence ◽  
Material Sciences ◽  
Optically Pure ◽  
Parallel Fashion

Abstract The first enantioselective assembly of sandwich-shaped organo molecules has been achieved by conducting dual asymmetric Suzuki-Miyaura couplings and nine other reactions. This work also presents the first fully C-C anchored multi-layer 3D chirality with optically pure enantiomers. As confirmed by X-ray diffraction analysis that this chiral framework is featured by a unique C2-symmetry in which a nearly parallel fashion consisting of three layers: top, middle and bottom aromatic rings. Unlike the documented planar or axial chirality, the present chirality shows its top and bottom layers restrict each other from free rotation, i.e., this multi-layer 3D chirality would not exist if either top or bottom layer is removed. Nearly all multi-layered compounds showed strong luminescence of different colors under UV irradiation, and several randomly selected samples displayed aggregation-induced emission (AIE) properties. This work is believed to have broad impacts on chemical, medicinal and material sciences including optoelectronic materials in future.

Exfoliated single molecular layers of Mn0.8PS3 and Cd0.8PS3

2005 ◽  
Vol 20 (5) ◽  
pp. 1107-1112 ◽  
Author(s):  
R.F. Frindt ◽  
D. Yang ◽  
P. Westreich
Keyword(s):  
Ion Exchange ◽  
Structure Factor ◽  
Single Layer ◽  
Layered Compounds ◽  
Two Dimensional ◽  
X Ray Diffraction ◽  
X Ray ◽  
Vacancy Ordering ◽  
Diffraction Patterns ◽  
Molecular Layers

The layered compounds MnPS3 and CdPS3 were exfoliated to form single molecular layers of Mn0.8PS3 and Cd0.8PS3 in suspension in water by ion exchange. The x-ray diffraction patterns of the two single-layer suspensions showed profound differences in some of the Bragg peaks, and we demonstrated that the differences are not due to the quality or size of the single layers, but are caused by structure factor modulations of the Warren tail for two-dimensional systems. We also demonstrated that the Cd or Mn vacancies generated in the exfoliation process are not ordered at long range, in contrast to an earlier report of vacancy ordering on intercalated MnPS3.

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