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  • What is GaSe?GaSe has been used as a semiconductor and a far-infrared conversion material at 14-31 THz and above. GaSe also finds applications in highly-efficient solar cells and battery technology. GaSe is a non-linear optical material with great potential in non-linear optical devices and THz generation. Recently, two-dimensional (2D) GaSe materials have drawn the increasing attention of researchers because of their superior performance in optical and electrical aspects. Hu et al. Reported a p What is yttrium nitride?Yttrium nitride is a dark gray powder, which is a kind of rare earth nitride. It has a very high melting point and keeps stable under high temperatures. So yttrium nitride can apply to refractory materials like titanium nitride and zirconium nitride. Yttrium nitride, Y5N14, was synthesized by a direct reaction between yttrium and nitrogen at ∼50 GPa and ∼2000 K in a laser-heated diamond anvil cell. High-pressure single-crystal X-ray diffraction revealed that the crystal s We synthesized pure polycrystalline cubic boron nitride (cBN) and wurtzite boron nitride (wBN) by the direct conversion method from hexagonal boron nitride. We measured their longitudinal-wave elastic constants CL between 20 and 300 K using picosecond ultrasound spectroscopy. Their room-temperature values are 945 ± 3 GPa and 930 ± 18 GPa for cBN and wBN, respectively. The shear modulus G of cBN was also determined by combining resonance ultrasound spectroscopy and micromechanics calculation as G Wurtzite boron nitride is a metastable superhard material that is a high-pressure polymorph of BN. Clarifying how the metastable high pressure material can be stabilized at atmospheric pressure is a challenging issue of fundamental scientific importance. Here, we fabricate millimeter-size w-BN bulk crystals via the hexagonal-to-wurtzite phase transformation at high pressure and temperatures. By combining transmission electron microscopy and ab initio molecular dynamics simulations, we reveal a s Micro-grains of wurtzite boron nitride(wBN) crystal have been observed in 5.0-7.0 GPa pressure and 1800-2000 K temperature where cubic boron nitride has been synthesized in a catalyst. The wBN grain size is about 20-30 nm. The presence of these micro grains indicates that the pressure for wBN growth could be lower than that found in the previous work. The first, wurtzite boron nitride, is similar to diamond but comprises different atoms. The second, the mineral lonsdaleite, is made from carbon a What is Wurtzite Boron Nitride?Wurtzite Boron Nitride (wBN) is a wide band gap BN polymorph with unique mechanical properties such as hardness and stiffness. Initially synthesized in 1963 by transforming hexagonal BN (hBN) under high temperature and pressure conditions, wBN can now be stabilized at atmospheric pressure to obtain high-quality samples. Our first-principles study investigates the electronic, vibrational, and optical properties of wBN across a broad range of pressures. We account fo What is Wurtzite boron nitride?Wurtzite boron nitride is a metastable superhard material that is a high-pressure polymorph of BN. Clarifying how the metastable high pressure material can be stabilized at atmospheric pressure is a challenging issue of fundamental scientific importance. Here, we fabricate millimeter-size w-BN bulk crystals via the hexagonal-to-wurtzite phase transformation at high pressure and temperatures. By combining transmission electron microscopy and ab initio molecular dyna Experimental and QM studies agree that the B4C crystal structure has rhombohedral symmetry with the R3̅m space group. The unit cell of B4C contains one 12-atom icosahedron located at the apexes of the primitive cell with one 3-atom linear chain aligned along the [111]r direction. Each icosahedron involves two crystallographic sites: six polar sites (p) connecting directly to other icosahedra and six equatorial sites (denoted as e) connecting with the 3-atom chains. The B4C structure was original What is Aluminum Boride?About Aluminum Boride: They are stable to nonoxidizing acids but break down into oxidising solid agents and alkalis. Borides are used in semiconductors, superconductors, diamagnetic, paramagnetic, ferromagnetic, anti-ferromagnetic, turbine blades, and rocket nozzles. It is a layered structure, with Al atoms directly overlapping (A, A mode), and B atoms are filled in the triangular column formed by the direct overlapping of Al atoms; the boron layer is between the two alum Titanium Aluminum Carbide MAX Phase Micron-Powder. Chemical Name: Titanium Aluminum Carbide. Titanium aluminum carbide belongs to the hexagonal crystal system and: it has the same conductivity or heat conduction as metal but has the same high elastic modulus and excellent high temperature mechanical properties as ceramic with good conductivity Ti₃AlC₂ is MAX Phase-like structured and crystallizes in the hexagonal P6₃/mmc space group. There are two inequivalent Ti sites. Ti is bonded in a 3-coord

Crystal structure and properties of Silicon nitride

The longer stacking sequence results in the α-phase having higher hardness than the β-phase. However, the α-phase is chemically unstable compared with the β-phase. When a liquid phase is present at high temperatures, the α-phase always transforms into the β-phase. Therefore, β-Si3N4 is the major form used in Si3N4 ceramics. Abnormal grain growth may occur in doped β-Si3N4, whereby abnormally large elongated grains form in a matrix of finer equiaxed grains and can serve as a technique to enhance

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Crystalline bulk silicon is rather inert

Crystalline bulk silicon is relatively inert but becomes more reactive at high temperatures. Still, the formation of the vitreous dioxide rapidly increases between 950 °C and 1160 °C, and when 1400 °C is reached, atmospheric nitrogen also reacts to give the nitrides SiN and Si3N4. Silicon reacts with gaseous sulfur at 600 °C and gaseous phosphorus at 1000 °C. This oxide layer nevertheless does not prevent reaction with the halogens; fluorine attacks silicon vigorously at room temperature, but i

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Silver coated quartz crystal microbalance resonator were covered with CuO nanostructures

Both sides (5 mm in diameter) of a silver-coated quartz crystal microbalance (QCM) resonator were covered with CuO nanostructures; the resonator was used as a sensing probe in a quartz crystal resonator. The resonant frequency shift indicates the absorbance of HCN gas on the sensor. As the specific area of CuO nanostructure used for coating the probe changes from 9.3 m2/g to 1.5 m2/g, the sensitivity reduces from 2.26 to 0.31 Hz/μg. In both reports, the authors showed that the sensitivity of sen

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CuO crystal has monoclinic structure

CuO crystal has a monoclinic structure and belongs to symmetry. Cupric oxide has four formula units per unit cell. The coordination number of copper atoms is 4, linked to four oxygen neighbor atoms in an approximately square planar configuration in the (110) plane. In all crystallized solids, divalent copper surroundings are invariably distorted by a strong Jahn-Teller effect which often leads to more stable square planar groups. The Cu-O bond lengths in this plane are 1.88 and 1.96 Å, respectiv

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Single Crystal Calcium Hexaboride Nanowires

Calcium hexaboride (CaB6), one of the divalent alkaline-earth cubic hexaborides, has low density (2.45 g/cm3 ), high melting point (2235 °C), high hardness (Knoop: 2600 kg/ mm2 ), high Young's modulus (379 GPa), and high chemical stability. CaB6 has found applications as a high-temperature material, used for surface protection, and is a wear-resistant material. CaB6 is also a promising candidate for n-type thermoelectric (TE) materials because its power factor has been reported to be larger than

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Iron(III) oxide phase with a monoclinic crystal structure

No iron(III) oxide phase with a monoclinic crystal structure stable at atmospheric pressure and room temperature has ever been identified. Thus, ζ-Fe2O3 can be regarded as a new iron(III) oxide polymorphic family member. It is known that the stability of nanoscale Fe2O3 polymorphs is governed by two factors: the Gibbs free energy of the different i-Fe2O3 phases (i = α, β, γ, ε) and the energy barrier associated with the phase transformation. These two parameters, in turn, depend on many factors,

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βFe2O3 was found to transform into a completely new crystal structure

Surprisingly, β-Fe2O3 was found to transform into a completely new crystal structure following the Rietveld refinement of the synchrotron radiation XRD patterns recorded at pressures above 30 GPa. The analyses were carried out adopting the following scenario. At high pressures (42.9–64.4 GPa), α-Fe2O3 transforms into RO-Fe2O3 and PPV-Fe2O3 with consistent transition pressures compared with the previous reports. On the other hand, β-Fe2O3 transits to a different new phase. By indexing these new p

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The effect of pressure treatment on the crystal structure of β Fe2O3

The effect of pressure treatment on the crystal structure of β-Fe2O3 was investigated using high-pressure synchrotron radiation XRD measurements. Representative high-pressure synchrotron XRD spectra and the detailed Rietveld analyses of all the measured synchrotron radiation XRD patterns (including the values of the Rwp-factor) are depicted in Supplementary Figures S1–S7 in the Supplementary Material. At up to 10 GPa pressures, the sample consists of β-Fe2O3 and α-Fe2O3 in approximately the same

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Crystalline Flake Graphite

What is graphite?This variety of Graphite is typically formed by the metamorphism of coal beds or carbon-rich sediments associated with igneous activity. It is generally a soft, darker black-colored graphite, less reflective than other varieties of natural crystalline Graphite. Commonly found as "microcrystalline" particles, this variety of Graphite has a lower graphitic carbon level when compared to other naturally occurring crystalline graphite varieties. The family of graphite materials inclu

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Titanium Diboride (TiB2) Micron Powder

What is Titanium diboride?A hot pressing process prepared titanium diboride (TiB2) and its ceramic composites. The sintering process, phase evolution, microstructure, and mechanical properties of TiB2 ceramics prepared by using different milling media materials: tungsten carbide (WC/Co) or SiAlON was studied. It was found that the inclusion of WC/Co significantly improved the sinterability of the TiB2 ceramics. A core/rim structure was identified with pure TiB2 as the core and W-rich TiB2, i.e.,

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Will clear quartz to replace any crystal

What is Quartz powder?Quartz is a strong and crystalline mineral made of silicon and oxygen particles. It is one of the most popular and rich minerals with various applications discovered on Earth. It is a significant element of rocks and applications in all temperatures. Quartz is transparent or white in its purest form, but several impurities within the atomic structure can change color. There are many varieties of quartz with several uses. Quartz sand and ground quartz or quartz powder are ut

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Titanium aluminum carbide (Ti3AlC2) belongs to the hexagonal crystal system

Titanium aluminum carbide (Ti3AlC2) belongs to the hexagonal crystal system and has the characteristics of metal and ceramics: it has the same conductivity and heat conduction as metal but also has the same high elastic modulus and excellent high-temperature mechanical properties as ceramic with good conductivity and heat conduction capability, high elastic modulus and low Vickers hardness, and good damage resistance capability. It can be machined at room temperature, producing plastic deformati

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What is nano-diamond?

The manufacture of nano-diamond , especially its application, has become a hot research topic in recent years. Nanodiamond has been developed more than 30 years ago, but its application in the past is limited to making polycrystalline, polis

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What are the functions of boron nitride

Overview of Boron nitride Powder Industrial-grade Boron nitride is a pure white ceramic material with the hexagonal structure of a crystal similar to graphite. The material can stand temperatures of more than 2,000 degC. Depending upon the grade, its dielectric strengths are close to 1000 volts/millimeter. The Boron Nitride is hot-pressed to its form as billets which are easily transformed into rods (bars), plates, rods and even customized shapes . What are the main functions of Boron Nitride

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Which calcium is best for seniors

Calcium citrate, calcium carbonate and calcium with vitamin D are some of the more popular supplements used by seniors to stay healthy and strong. Hypercalcemia is when the calcium level in your blood is above normal. Too much calcium in your blood can weaken your bones, create kidney stones, and interfere with how your heart and brain work. Hypercalcemia is usually a result of overactive parathyroid glands. In the case of men and women taking medication, such as Fosamax or Evenity, for osteopor

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