Cu-deficiency induced structural transition of Cu2−xTe

CrystEngComm ◽  
2015 ◽  
Vol 17 (14) ◽  
pp. 2878-2885 ◽  
Author(s):  
Lei Yu ◽  
Kun Luo ◽  
Shiyou Chen ◽  
Chun-Gang Duan
Keyword(s):  
Phase Separation ◽  
Structural Transition ◽  
Monoclinic Structure ◽  
Cu Deficiency ◽  
Trigonal Structure

All the reported structures of Cu2Te are found to be metastable with respect to the phase separation Cu2Te → Cu2−xTe + xCu, which causes a structural transition of Cu2−xTe from the monoclinic structure (stable when x = 0) to the trigonal structure (0.125 ≤ x ≤ 0.625). The experimental XRD peaks of Cu2−xTe samples should be attributed to the trigonal structure.

Enhancement of Fluorescence in Colloidal CuInS2 Nanocrystals by Introduction of Crystal Defect

2009 ◽  
Vol 1176 ◽  
Author(s):  
Masato Uehara ◽  
Kosuke Watanabe ◽  
Yasuyuki Tajiri ◽  
Hiroyuki Nakamura ◽  
Hideaki Maeda
Keyword(s):  
Phase Separation ◽  
Quantum Yield ◽  
Metal Complexes ◽  
Fluorescence Intensity ◽  
Fluorescence Quantum Yield ◽  
Bulk Material ◽  
Crystal Defects ◽  
Crystal Defect ◽  
Cu Deficiency ◽  
Cuins2 Nanocrystals

AbstractCu-In-S nanocrystals were developed as a low toxic fluorescent. The stoichiometric CuInS2 nanocrystals were synthesized facilely by heating a solution of metal complexes. The fluorescence would be originated from the crystal defect. We intentionally introduced the crystal defects related to Cu deficiency in nanocrystal with the prospect that the fluorescence intensity would be increased. The nanocrystals have many defects without phase separation as observed in bulk material. Consequently, the fluorescence quantum yield achieved to c.a. 6%. Moreover, the fluorescence quantum yield was increased up to 15% by the ZnS-coating.

scholarly journals Nanosized hydroxyapatite and β-tricalcium phosphate composite: Physico-chemical, cytotoxicity, morphological properties and in vivo trial

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Igor da Silva Brum ◽  
Jorge José de Carvalho ◽  
Jorge Luis da Silva Pires ◽  
Marco Antonio Alencar de Carvalho ◽  
Luiza Braga Ferreira dos Santos ◽  
...  
Keyword(s):  
Tricalcium Phosphate ◽  
Morphological Properties ◽  
Sinus Lift ◽  
Monoclinic Structure ◽  
Manufacturing Control ◽  
Physico Chemical ◽  
Synthetic Biomaterial ◽  
Trigonal Structure ◽  
High Level

AbstractThe objective of this work was to characterize the properties of a synthetic biomaterial composite with nanoparticles size (Blue Bone). This biomaterial is a composite recommended for dental and orthopedic grafting surgery, for guided bone regeneration, including maxillary sinus lift, fresh alveolus filling, and treatment of furcation lesions. The nano biomaterials surface area is from 30% to 50% higher than those with micro dimensions. Another advantage is that the alloplastic biomaterial has homogeneous properties due to the complete manufacturing control. The analyzed biomaterial composite was characterized by XRD, cytochemistry, scanning electron microscopy, porosimetry and in vivo experiments (animals). The results showed that the analyzed biomaterial composite has 78.76% hydroxyapatite [Ca5(PO4)3(OH)] with monoclinic structure, 21.03% β-tricalcium phosphate [β -Ca3(PO4)2] with trigonal structure and 0.19% of CaO with cubic structure, nanoparticles with homogeneous shapes, and nanoporosity. The in vivo experiments showed that the composite has null cytotoxicity, and the site of insertion biomaterials has a high level of vascularization and bone formation. The conclusion is that the synthetic biomaterial with Blue Bone designation presents characteristics suitable for use in grafting surgery applications.

Structural Systematics of the High-Pressure Phases of Phosphorus, Arsenic, Antimony and Bismuth

1997 ◽  
Vol 53 (3) ◽  
pp. 353-357 ◽  
Author(s):  
H. Iwasaki ◽  
T. Kikegawa
Keyword(s):  
High Pressure ◽  
Structure Data ◽  
Layered Structure ◽  
Structural Transition ◽  
Atomic Plane ◽  
Body Centered Cubic ◽  
Monoclinic Structure ◽  
Transition Sequence ◽  
Simple Cubic ◽  
Cubic Structure

New structural systematics of the high-pressure phases of the title elements are given on the basis of the results obtained in our diffraction studies and the results from the literature. Although the structural transition sequence with increasing pressure appears to be different for the four elements, reinterpretation of the structure data has shown that it is expressed in a systematic way as follows P A17–A7–PSC As A7–PSC–dist. BCC–BCC Sb A7–dist. BCC–BCC Bi A7–dist. PSC–dist. BCC–BCC. Notations used are A17 (orthorhombic layered structure), A7 (rhombohedral layered structure), PSC (primitive simple cubic structure), dist. PSC (monoclinic structure which is regarded as a distorted PSC), BCC (body-centered cubic structure) and dist. BCC (tetragonal structure which is regarded as a distorted BCC). Phosphorus lacks the post-PSC phases, but it is likely that the same transition sequence as that of arsenic is seen under extremely high pressure. Discussion is made on how the network of the densest atomic plane changes through the structural transition sequence.

scholarly journals Phase Separation on a Phospholipid Membrane Inducing a Characteristic Localization of DNA Accompanied by Its Structural Transition

2010 ◽  
Vol 1 (23) ◽  
pp. 3391-3395 ◽  
Author(s):  
Ayako Kato ◽  
Akihiko Tsuji ◽  
Miho Yanagisawa ◽  
Daisuke Saeki ◽  
Kazuhiko Juni ◽  
...  
Keyword(s):  
Phase Separation ◽  
Structural Transition ◽  
Phospholipid Membrane ◽  
Characteristic Localization

scholarly journals Influence of the Growth Ambience on the Localized Phase Separation and Electrical Conductivity in SrRuO3 Oxide Films

Coatings ◽  
2019 ◽  
Vol 9 (9) ◽  
pp. 589
Author(s):  
Hsin-Ming Cheng
Keyword(s):  
Thin Films ◽  
Electrical Conductivity ◽  
Phase Transformation ◽  
Phase Separation ◽  
Structural Transition ◽  
Pulsed Laser ◽  
Laser Deposition ◽  
Epitaxial Thin Films ◽  
High Quality ◽  
Epitaxial Oxide

Perovskite SrRuO3 (SRO) epitaxial thin films grown on SrTiO3 (STO) (001) have been synthesized using pulsed laser deposition (PLD) under a series of oxygen pressures. High quality and conductive SRO thin films on STO have been achieved at 10−1 Torr oxygen pressure with the epitaxial relation of (110)<001>SrRuO3//(001)<010>SrTiO3. The lattice parameters of the thin films exhibit huge expansion by reducing the ambience (~10−7 Torr) during deposition, and the resistance increases by about two orders higher as compared with the low oxide pressure ones. The rise of resistivity can be ascribed to not only the deficiency of Ru elements but also the phase transformation inside SRO thin films. The correlation of growth ambience on the structural transition and corresponding resistivity of epitaxial oxide thin films have been explicitly investigated.

scholarly journals Analisis Mineral Tanah Rawan Longsor Menggunakan X-Ray Diffraction Di Desa Sawaru Kabupaten Maros

2020 ◽  
Vol 2 (1) ◽  
pp. 41-49
Author(s):  
Rahmaniah Rahmaniah ◽  
Reskywijaya Reskywijaya ◽  
Ayu Sari Wahyuni ◽  
Harsano Jayadi
Keyword(s):  
Xrd Analysis ◽  
Slope Instability ◽  
High Plasticity ◽  
Monoclinic Structure ◽  
X Ray Diffraction ◽  
X Ray ◽  
Mineral Characteristics ◽  
Prone Area ◽  
Trigonal Structure ◽  
Triclinic Structure

The study of soil minerals structure has been conducted in the Sawaru village, Maros regency, South Sulawesi which is locally known to be the landslides-prone area. The aim of this research is basically to determine the mineral characteristics of the soil. The samples were taken randomly in three points with a depth of 75 cm at point 1 and 100 cm for the other. The structure of the samples was analyzed using X-Ray Diffraction (XRD) where the samples were placed in the high temperature and airtight containers. The results of XRD analysis showed that minerals contained at point 1 (75 cm in depth) were illite (69.3%) with a monoclinic structure, albit mineral (25.6%) with a triclinic structure and kaolinite (5.0%) with a triclinic structure. Samples at point II (100 cm depth) contained illite (67.2%), feldspar (23.9%) with monoclinic and merrillit (8.9%) with trigonal structures. Samples at point III (100 cm in depth) contained illite (55.9%), bobtraillite (22.2%) with a trigonal structure and feldspar (21.9%) with a monoclinic structure. The minerals observed at the sampling points are dominated by illite which is clay in nature. Such a mineral has been known to have an ability to initiate high plasticity in soil, leading to the slope instability.

Bulk standards for low-temperature biological x-ray microanalysis

1984 ◽  
Vol 42 ◽  
pp. 282-283
Author(s):  
P. Echlin ◽  
M. McKoon ◽  
E.S. Taylor ◽  
C.E. Thomas ◽  
K.L. Maloney ◽  
...  
Keyword(s):  
Phase Separation ◽  
Low Temperature ◽  
Analytical Method ◽  
Salt Solutions ◽  
Absolute Concentration ◽  
Cooling Process ◽  
X Ray ◽  
The Absolute ◽  
Analytical Procedures ◽  
Electrical Conductors

Although sections of frozen salt solutions have been used as standards for x-ray microanalysis, such solutions are less useful when analysed in the bulk form. They are poor thermal and electrical conductors and severe phase separation occurs during the cooling process. Following a suggestion by Whitecross et al we have made up a series of salt solutions containing a small amount of graphite to improve the sample conductivity. In addition, we have incorporated a polymer to ensure the formation of microcrystalline ice and a consequent homogenity of salt dispersion within the frozen matrix. The mixtures have been used to standardize the analytical procedures applied to frozen hydrated bulk specimens based on the peak/background analytical method and to measure the absolute concentration of elements in developing roots.

Phase separation in sol gel-derived ceramic films of silica-zirconia, alumina-zirconia, and titania-zirconia system

1994 ◽  
Vol 52 ◽  
pp. 646-647
Author(s):  
J. Tong ◽  
L. Eyring
Keyword(s):  
Fracture Toughness ◽  
Phase Separation ◽  
Sol Gel ◽  
Great Influence ◽  
High Strength ◽  
Chemical Durability ◽  
Separation Method ◽  
Toughening Mechanism ◽  
Ceramic Films ◽  
Zirconia Toughened Alumina

There is increasing interest in composites containing zirconia because of their high strength, fracture toughness, and its great influence on the chemical durability in glass. For the zirconia-silica system, monolithic glasses, fibers and coatings have been obtained. There is currently a great interest in designing zirconia-toughened alumina including exploration of the processing methods and the toughening mechanism.The possibility of forming nanocrystal composites by a phase separation method has been investigated in three systems: zirconia-alumina, zirconia-silica and zirconia-titania using HREM. The morphological observations initially suggest that the formation of nanocrystal composites by a phase separation method is possible in the zirconia-alumina and zirconia-silica systems, but impossible in the zirconia-titania system. The separation-produced grain size in silica-zirconia system is around 5 nm and is more uniform than that in the alumina-zirconia system in which the sizes of the small polyhedron grains are around 10 nm. In the titania-zirconia system, there is no obvious separation as was observed in die alumina-zirconia and silica-zirconia system.

Phase separation in fluid additive hard sphere mixtures?

1998 ◽  
Vol 95 (2) ◽  
pp. 131-135 ◽  
Author(s):  
DOUGLAS HENDERSON DEZSO BODA KWONG-YU CHAN
Keyword(s):  
Phase Separation ◽  
Hard Sphere

The plant response to heat requires phase separation

Nature ◽  
2020 ◽  
Vol 585 (7824) ◽  
pp. 191-192 ◽  
Author(s):  
Simon Alberti
Keyword(s):  
Phase Separation ◽  
Plant Response
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