Состав, структура, полупроводниковые свойства химически осажденных пленок SnSe

High adhesion tin monoselenide SnSe layers with a thickness of up to 200 ± 10 nm have been prepared by hydrochemical deposition from a trilonate reaction mixture. It was revealed by the X-ray diffraction method that the synthesized films crystallize in the orthorhombic system (S. G. Pnma). The presence of a significant amount of oxygen in the surface layers of the films is explained by partial oxidation of the samples with the formation of the SnO2 phase. The results of ion etching to a depth of 18 nm showed a sharp decrease in the oxygen content with depth and actual correspondence of the elemental composition to SnSe. According to the results of optical studies, the band gap was found to be 1.69 eV for direct type of transitions, respectively. The synthesized SnSe layers have a hole-type conductivity typical of this material.

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Phase analysis of bulk samples using sample-tilting X-ray diffractometry

Journal of Applied Crystallography ◽

10.1107/s0021889892004412 ◽

1992 ◽

Vol 25 (5) ◽

pp. 582-588 ◽

Cited By ~ 8

Author(s):

Q. Cong

Keyword(s):

Phase Analysis ◽

Diffraction Method ◽

Sample Surface ◽

Geometrical Optics ◽

Crystal Plane ◽

X Ray Diffraction ◽

Surface Layers ◽

Depth Of Penetration ◽

X Ray ◽

Surface Reflection

In the Bragg–Brentano X-ray powder diffractometer, the sample-tilting X-ray diffraction (STD) technique probes a fixed depth of penetration from the sample surface. In this way, phase analysis can be carried out from the surface layers to the depth probed by the CBD (conventional Bragg–Brentano geometry X-ray diffraction) method. In the present paper, after derivation of the diffracted intensity and the observed crystal-plane azimuthal equations, attention is focused on investigations of the geometrical optics of X-ray surface reflection by comparing the STD and CBD methods. Some examples are given to illustrate the applications of the STD technique for solving phase analyses and related problems.

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A NOVEL OCTAHEDRAL NIOBIUM OXYCHLORIDE CLUSTER BUILT FROM INTERCONNECTED Nb6Cl12O4 UNITS: Cs2Sc3Nb1227O8

Indonesian Journal of Chemistry ◽

10.22146/ijc.21396 ◽

2011 ◽

Vol 11 (2) ◽

pp. 109-116

Author(s):

Fakhili Gulo

Keyword(s):

Crystal Structure ◽

Solid State ◽

Three Dimensional ◽

Diffraction Method ◽

X Ray Diffraction ◽

Stoichiometric Mixture ◽

Orthorhombic System ◽

X Ray ◽

Solid State Route ◽

Valence Electrons

A novel octahedral niobium cluster oxychloride compound, Cs2Sc3Nb12Cl27O8 was synthesized by solid-state route techniques from stoichiometric mixture of CsCl, Sc2O3, Nb, NbCl5, and Nb2O5, heated at 700 °C for two days. The crystal structure was determined by single crystal X-ray diffraction method. It crystallizes in orthorhombic system with space group of Pnma, a = 17.5206(1) Å, b = 29.6899(3) Å, c = 9.2114(1) Å, and V = 4791.63(8) Å3. The structure is based on unit in which four oxygen ligands selectively occupy inner positions arranged in sets of three and one on opposite side of the Nb6 octahedron. Each cluster shares three apical-chlorine ligands with three adjacent clusters to form layers with topology similar to that of graphite. The cluster units are also connected to each other by both cesium and scandium atoms to form a three-dimensional framework. This compound exhibits 14 valence electrons per cluster.

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X‐ray diffraction method for characterization of thin surface layers and thin epitaxial films

Applied Physics Letters ◽

10.1063/1.108841 ◽

1993 ◽

Vol 62 (7) ◽

pp. 690-692 ◽

Cited By ~ 6

Author(s):

Nobuo Itoh

Keyword(s):

Diffraction Method ◽

Epitaxial Films ◽

X Ray Diffraction ◽

Surface Layers ◽

X Ray

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An X-ray diffraction method for semiquantitative mineralogical analysis of Chilean nitrate ore

Open-File Report ◽

10.3133/ofr94240 ◽

1994 ◽

Cited By ~ 3

Author(s):

J.C. Jackson ◽

G.E. Ericksen

Keyword(s):

Diffraction Method ◽

X Ray Diffraction ◽

Mineralogical Analysis ◽

X Ray

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Growth of sillenite Bi12FeO20 single crystals: structural, thermal, optical, photocatalytic features and first principle calculations

Scientific Reports ◽

10.1038/s41598-020-78598-3 ◽

2020 ◽

Vol 10 (1) ◽

Author(s):

Durga Sankar Vavilapalli ◽

Ambrose A. Melvin ◽

F. Bellarmine ◽

Ramanjaneyulu Mannam ◽

Srihari Velaga ◽

...

Keyword(s):

Single Crystal ◽

Single Crystals ◽

Photoelectron Spectroscopy ◽

Diffraction Method ◽

Lattice Parameter ◽

First Principle ◽

X Ray Diffraction ◽

X Ray ◽

First Principle Calculations ◽

Photodegradation Efficiency

AbstractIdeal sillenite type Bi12FeO20 (BFO) micron sized single crystals have been successfully grown via inexpensive hydrothermal method. The refined single crystal X-ray diffraction data reveals cubic Bi12FeO20 structure with single crystal parameters. Occurrence of rare Fe4+ state is identified via X-ray photoelectron spectroscopy (XPS) and X-ray absorption spectroscopy (XAS). The lattice parameter (a) and corresponding molar volume (Vm) of Bi12FeO20 have been measured in the temperature range of 30–700 °C by the X-ray diffraction method. The thermal expansion coefficient (α) 3.93 × 10–5 K−1 was calculated from the measured values of the parameters. Electronic structure and density of states are investigated by first principle calculations. Photoelectrochemical measurements on single crystals with bandgap of 2 eV reveal significant photo response. The photoactivity of as grown crystals were further investigated by degrading organic effluents such as Methylene blue (MB) and Congo red (CR) under natural sunlight. BFO showed photodegradation efficiency about 74.23% and 32.10% for degrading MB and CR respectively. Interesting morphology and microstructure of pointed spearhead like BFO crystals provide a new insight in designing and synthesizing multifunctional single crystals.

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Study of Corrosion Resistance and Degradation Mechanisms in LiTiO2-Li2TiO3 Ceramic

Crystals ◽

10.3390/cryst11070753 ◽

2021 ◽

Vol 11 (7) ◽

pp. 753

Author(s):

Dmitriy Shlimas ◽

Artem L. Kozlovskiy ◽

Maxim Zdorovets

Keyword(s):

Degradation Mechanism ◽

Diffraction Method ◽

Large Mass ◽

Time Frame ◽

X Ray Diffraction ◽

Acidic Media ◽

X Ray ◽

Mass Losses ◽

The Stability ◽

Thermal Sintering

The interest in lithium-containing ceramics is due to their huge potential as blanket materials for thermonuclear reactors for the accumulation of tritium. However, an important factor in their use is the preservation of the stability of their strength and structural properties when under the influence of external factors that determine the time frame of their operation. This paper presents the results of a study that investigated the influence of the LiTiO2 phase on the increasing resistance to degradation and corrosion of Li2TiO3 ceramic when exposed to aggressive acidic media. Using the X-ray diffraction method, it was found that an increase in the concentration of LiClO4·3H2O during synthesis leads to the formation of a cubic LiTiO2 phase in the structure as a result of thermal sintering of the samples. During corrosion tests, it was found that the presence of the LiTiO2 phase leads to a decrease in the degradation rate in acidic media by 20–70%, depending on the concentration of the phase. At the same time, and in contrast to the samples of Li2TiO3 ceramics, for which the mechanisms of degradation during a long stay in aggressive media are accompanied by large mass losses, for the samples containing the LiTiO2 phase, the main degradation mechanism is pitting corrosion with the formation of pitting inclusions.

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