Influence of oxygen partial pressure on microstructure, optical
Introduction. Hafnium oxide (HfO 2) is a refractory oxide ceramic material, which exhibits high melting point, wide band gap, high refractive index and high laser induced damage threshold [[1], [2], [3]].HfO 2 is widely used to fabricate various optical coating devices in the spectral region from ultraviolet to near infrared required for …Web
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[PDF] In-situ zircon UPb, oxygen and hafnium isotopic 1 …
In-situ zircon UPb, oxygen and hafnium isotopic 1 evidence for magma mixing and mantle 2 metasomatism in the Tuscan Magmatic Province, 3 ItalyWeb
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Zircon U–Pb, oxygen, and hafnium isotopic
Oxygen (δ18O 5.27 to 7.45 ‰) and hafnium (ɛHf(t) -27.8 to -12.3) isotopic data from plutons in the Itremo and Antananarivo Domains are consistent with incorporation of an ancient crustal source.Web
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Hafnium Oxide Could Boost Semiconductor Performance
Samantha Jaszewski, a National Science Foundation graduate research fellow and part of the research team developed the HiPIMS processes to prepare hafnium oxide films. "We were sputtering from a metallic hafnium target and utilizing oxygen in the plasma gas to oxidize the deposit," said Ihlefeld. "As Samantha prepared films under a …Web
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Ultrahigh-Temperature HfB 2 -Based Ceramics: Structure, High
Ultrahigh-temperature hafnium diboride ceramics with additions of 15 vol.% MoSi2 or 15 vol.% SiC or a combined addition of 15 vol.% SiC and 5 vol.% WC were produced by hot pressing in the range 1800–2000°C. The density of the produced composite ceramics was >98%. The components interacted in the hot pressing process to form new …Web
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Zircon U-Pb, oxygen, and hafnium isotopic characteristics of the
The Neoarchean to Paleoproterozoic Betsiboka Suite of Madagascar mainly consists of granitoid orthogneiss and migmatite variably metamorphosed to amphibolite and granulite facies during the late Neoproterozoic. New U-Pb zircon data yield emplacement ages of 2512 ± 17, 2507 ± 17, 2493 ± 14 and 2485 ± 16 Ma. Zircon δ 18 O data indicate …Web
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Hafnium | History, Uses, Facts, Physical & Chemical Characteristics
Hafnium also react with carbon, oxygen, sulfur and nitrogen, at elevated temperatures. Hafnium nitride is characterized as the most refractory of all nitrides of metals, and it has melting point of as high as 3310°C. So, it can withstand high temperatures. It has significant nuclear properties as it can absorb high thermal neutrons, whereas ...Web
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Fabrication and high-temperature performance evaluation of …
Section snippets Experiment. 1. Fabrication of the silicon carbide-hafnium carbide nanocomposite fiber. Polycarbosilane (M w = 3.56 × 10 3 g/mol, Polymer dispersion index (PDI) = 2.71) was synthesized in our laboratory based on a previously reported method [26]. Hafnium (IV) acetylacetonate (Mw = 320.97 g/mol, > 99% assay) and …Web
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U-Pb and 207Pb-206Pb ages of zircons from basaltic eucrites
An oxygen (O 2 −) primary beam of ... Hafnium, Uranium, and Thorium Abundances in Eucritic ZirconEucritic zircon commonly contains a certain amount of hafnium (Table 3). The hafnium contents of zircons in unmetamorphosed, metamorphosed, granulitic and shocked eucrites range from 0.53 wt% to 1.42 wt%. There are no …Web
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X-Ray Photoemission Study of the Oxidation of Hafnium
A. R. Chourasia. S. H. McKinney. Core levels and x-ray excited Auger regions of hafnium and oxygen in elemental hafnium and hafnium dioxide have been investigated by x-ray photoelectron ...Web
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Extended periodic table
Layout. The extended periodic table is a version of the periodic table that is longer than the normal one, making room for future synthetic elements. The inner transition metals are placed between Group 2 and Group 3 on the periodic table. On a normal periodic table, the inner transition metals are below Groups 2 and 3.Web
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U-Pb dating, oxygen and hafnium isotopic ratios of zircon from …
U-Pb dating, oxygen and hafnium isotopic ratios of zircon from rocks of oceanic core complexes at Mid-Atlantic Ridge: evidence for an interaction of young and ancient crusts at spreading of the ocean floor. U-Pb-датирование, соотношение изотопов кислорода и гафния в цирконе пород ...Web
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Preferential dissolution of uranium-rich zircon can bias the hafnium
hafnium and oxygen isotopes in zircons to unrav-el the record of crustal evolution: Chemical Geol- ... New zircon UPb data suggest an emplacement age of 327–324 Ma for trondhjemite, which ...Web
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U–Pb Dating, Oxygen and Hafnium Isotope Ratios of Zircon
Abstract. The U–Pb age and oxygen and hafnium isotope ratios of zircon from rocks of oceanic core complexes along the Mid-Atlantic Ridge have been studied …Web
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Plešovice zircon — A new natural reference material for U–Pb …
A reconnaissance ion-probe study of hafnium isotopes in zircons. Geochimica et Cosmochimica Acta (1991) ... The calculated values of oxygen fugacity for the Beidashan pluton range from −19.3 to −15.7, and most of them are lower than the fayalite-magnetite-quartz (FMQ) oxygen buffer. Apatite in the Beidashan pluton has high …Web
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Atomic Layer of Deposition of Ferroelectric HfO2
the hafnium precursor and the exposed hydroxyl groups. The result of this is the hafnium atoms bonded to the oxygen atoms from the hydroxyl groups and dimethylamine, (CH 3) 2NH, as a by-product. The chamber is then purged, removing all unreacted hafnium precursor and dimethylamine by-product. DI water is then pulsed into the chamber toWeb
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Wake-up effects in Si-doped hafnium oxide ferroelectric thin films
Hafnium oxide based ferroelectric thin films have shown potential as a promising alternative material for non-volatile memory applications. This work reports the switching stability of a Si-doped HfO2 film under bipolar pulsed-field operation. High field cycling causes a "wake-up" in "pinched" polarization hysteresis loops, …Web
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PHYSICAL REVIEW B104, L180102 (2021)
PHYSICAL REVIEW B104, L180102 (2021) Letter Ferroelectric structural transition in hafnium oxide induced by charged oxygen vacancies Ri He, 1,*Hongyu Wu, Shi Liu,2 Houfang Liu,3 and Zhicheng Zhong 4 † 1Key Laboratory of Magnetic Materials Devices & Zhejiang Province Key Laboratory of Magnetic Materials and Application Technology, …Web
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Combined U–Pb, hafnium and oxygen isotope analysis of
Combined U–Pb, hafnium and oxygen isotope analysis of zircons from meta-igneous rocks in the southern North China Craton reveal multiple events in the …Web
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Zircon oxygen and hafnium isotope decoupling during regional
Oxygen diffusion coefficients even under wet conditions and elevated temperatures (850°C) are ≤ 1–3 × 10−23 m2/s, underscoring a virtual lack of oxygen diffusion and an outstanding ...Web
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Hafnium
Uses. Hafnium is a good absorber of neutrons and is used to make control rods, such as those found in nuclear submarines. It also has a very high melting point and because of this is used in plasma welding torches. Hafnium has been successfully alloyed with several metals including iron, titanium and niobium.Web
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Zircon M127 – A Homogeneous Reference Material for SIMS …
Zircon M127 est proposé comme matériau de référence pour la détermination des âges U-Pb de zircon par SIMS en combinaison avec des analyses sur l'hafnium et des isotopes stables (l'oxygène et éventuellement aussi le lithium).Web
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Study of the Possibility of Recycling of Technogenic Hafnium …
The possibility of removing metallic (such as Zr, Fe, Cr, and Zn) impurities and non-metallic (such as [O] and C) impurities from technogenic hafnium through single and double refining in the conditions of electron beam melting (EBM) has been studied. The influence of thermodynamic and kinetic parameters on the degree of removal of these impurities from …Web
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Simultaneous determinations of U–Pb age, Hf isotopes
For methods UPb and UPbTr, we used a routine LA-Q-ICP-MS protocol that consisted of 30 s of blank acquisition prior to a 50 s ablation of the zircon (laser frequency, 10 Hz; spot size, 32 μm). ... Using hafnium and oxygen isotopes in zircons to unravel the record of crustal evolution. Chem. Geol., 226 (2006), 10.1016/j.chemgeo.2005.09.018 ...Web
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Geochemistry, zircon U-Pb geochronology and Hf-O
The oxygen fugacity of melts and fluids is a key factor controlling the formation of porphyry-type deposits (Wang et al., 2014b, Wang et al., 2014c). The Ce 4+ /Ce 3+ and δEu values of magmatic zircon can be used to qualitatively estimate the oxygen fugacity of magmas ( Ballard et al., 2002 ), where higher Ce 4+ /Ce 3+ and δEu values …Web
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Electronic properties of hafnium oxide: A contribution
Independent evidence for the presence of oxygen vacancies in HfO x can be obtained via a comparison of experimental XPS spectra of the valence band of HfO 2 with the spectra obtained in ab initio calculations of monoclinic hafnium oxide (Fig. 1 (b)). The calculated data rather adequately represent experimental spectra if one takes into …Web
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Rutile's fiery brilliance | Nature Geoscience
Full size image. Rutile is the most thermodynamically stable form of titanium dioxide — TiO 2 — under most geologic conditions, and typically occurs as an accessory mineral in metamorphic and ...Web
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U-Pb Dating, Oxygen and Hafnium Isotope Ratios of Zircon
The U-Pb age and oxygen and hafnium isotope ratios of zircon from rocks of oceanic core complexes along the Mid-Atlantic Ridge have been studied using SHRIMP and MC-LA …Web
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Early Cretaceous ridge subduction beneath southern
This study presents new oxygen and hafnium isotope analyses, and U/Pb geochronology on the Crawfish Inlet Pluton and the Krestof Pluton, from the eastern part …Web
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Oxygen and nitrogen diffusion in α-hafnium from first principles
Comparing the local density approximation and the Perdew-Burke-Ernzerhof version of the generalized gradient approximation, we find that a better description of the hafnium lattice in the latter results in the correct sequence of stable and transition states for oxygen interstitials leading to essentially quantitative agreement with experiment.Web
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