Another route to ferroelectric HfO2 | Nature Materials
Another route to ferroelectric HfO. 2. Observation of large remnant polarization in epitaxial yttrium-doped hafnium oxide thin films demonstrates that small-grained or ultrathin microstructures ...
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Metallography and Microstructures of Zirconium, …
Metallography and Microstructures of Zirconium, Hafnium, and Their Alloys. Authors: Paul E. Danielson. Richard C. Sutherlin. Request full-text. Abstract. …
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Zirconium and hafnium
US import zirconium prices increased at a CAGR of 18% from US$311/t in 1999 to US$2,500/t in 2012 before falling 53% to US$1,207/t by 2014. The current zircon price is around US$1,013/t and the hafnium price is around US$850,000/t. Experts expect zircon prices to continue to rise over the mid-term, reaching US$1,400/t by 2021, driven …
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Unveiling the Origin of Robust Ferroelectricity in Sub-2 nm Hafnium …
Herein, we solve the mystery for the continuous retention of high ferroelectricity in an ultrathin hafnium zirconium oxide (HZO) film (∼2 nm) by unveiling the evolution of microstructures and crystallographic orientations using a combination of state-of-the-art structural analysis techniques beyond analytical limits and theoretical approaches.
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Zirconium and Hafnium | Metals Handbook Desk Edition
This article discusses the general characteristics, primary and secondary fabrication methods, product forms, and corrosion resistance of zirconium and hafnium. It describes the physical metallurgy of zirconium and its alloys, providing details on allotropic transformation and anisotropy that profoundly influences the engineering properties of ...
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Nd Fe B anisotropic magnet powders produced by the …
The substitution of iron with cobalt and the addition of elements such as gallium, zirconium, niobium, hafnium and tantalum was found to be very effective in inducing the magnetic anisotropy in Nd-Fe-B magnet powders. The average crystalline grain size in the magnet powder is about 0.3 ~tm and the shape of grains is nearly spherical.
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Zirconium and Hafnium
Zirconium, hafnium, and titanium are produced from ore that generally is found in a heavy beach sand containing zircon, rutile, and ilmenite. This article discusses the processing methods of these metals, namely, liquid-liquid separation process, distillation separation process, refining, and melting.
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Zirconium and hafnium | U.S. Geological Survey
December 19, 2017. Zirconium and hafnium are corrosion-resistant metals that are widely used in the chemical and nuclear industries. Most zirconium is consumed in the form of …
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Densification and Mechanical Behavior of HfC and HfB
Hafnium diboride (HfB 2)- and hafnium carbide (HfC)-based materials containing MoSi 2 as sintering aid in the volumetric range 1%–9% were densified by spark plasma sintering at temperatures between 1750° and 1950°C. Fully dense samples were obtained with an initial MoSi 2 content of 3 and 9 vol% at 1750°–1800°C. When the …
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[PDF] Ultra-high temperature ceramics: Materials for extreme
Compositional dependence of optical properties of zirconium, hafnium and tantalum carbides for solar absorber applications. ... The ultra‐high temperature experienced by the Tantalum carbide samples resulted in the formation of many interesting microstructures, including theformation of submicron sized grains, which has not been …
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Metallography and Microstructures of Zirconium, Hafnium, …
Abstract. Zirconium, hafnium, and their alloys are reactive metals used in a variety of nuclear and chemical processing applications. This article describes var
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Zirconium and Hafnium Statistics and Information
Statistics and information on the worldwide supply of, demand for, and flow of the mineral commodities zirconium and hafnium. The principal economic source of zirconium is the …
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Phase Exchange Driven Wake-Up and Fatigue in Ferroelectric Hafnium …
Insight is provided into the role of electrodes on the performance of hafnium oxide-based ferroelectrics, mechanisms driving wake-up and fatigue, and a non-destructive means to characterize the phase changes accompanying polarization instabilities are demonstrated. Ferroelectric hafnium zirconium oxide holds great promise for a broad …
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Zirconium/hafnium fractionation and rare earth element
All garnet-bearing mantle lithologies in the WGR contain oriented mineral microstructures that formed after majoritic garnet (van Roermund and Drury 1998; Spengler et al. 2006 ... D., Opitz, J. Zirconium/hafnium fractionation and rare earth element systematics in sub-cratonic garnet pyroxenites, Norway. Contrib Mineral Petrol 178, 59 ...
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Investigation of Hafnium Oxide Containing Zirconium in the …
Surface scale is usually formed in the aerofoil part of as-cast nickel-based single crystal turbine blades by the strong interaction between the mould wall and the melt, and the subsequent oxidation of the fresh metallic surface of the casting. For better understanding of the scaling, the scaled region was investigated, and an interesting …
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Volume 9 Metallography and Microstructures
Metallography and Microstructures of Zirconium, Hafnium, and Their Alloys 6. Metallography and Microstructures of Ceramics, Composite-Metal Forms, and Special-Purpose Alloys Metallography of Biomedical Orthopedic Alloys Microstructure and Domain Imaging of Magnetic Materials
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192 ZIRCONIUM AND HAFNIUM
Zirconium and hafnium are typically contained in zircon at a ratio of about 36 to 1. Zirconium chemicals were produced by the metal producer in Oregon and by at least 10 …
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Interface-engineered ferroelectricity of epitaxial …
Ali, T. et al. Silicon doped hafnium oxide (HSO) and hafnium zirconium oxide (HZO) based FeFET: a material relation to device physics. Appl. Phys. Lett. 112, 222903 (2018).
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Zirconium Alloys for Orthopedic Applications | SpringerLink
Abstract. Physical and chemical properties of zirconium (Zr) are introduced and the features and differences from titanium (Ti) are pointed out. Zr is principally applied to the nuclear power industry because of its low thermal neutron cross section. For medical applications, a Zr alloy (Zr-2.5Nb) is used in total knee and hip replacements ...
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Phase equilibria in the ZrO2–HfO2–Sm2O3 system at 1500 °С
In this work, the interaction of zirconium, hafnium and samarium oxides at 1500 °С in the whole range of concentrations was studied for the first time and a corresponding isothermal cross section was constructed. ... Microstructures were studied using a scanning electron microscope SUPERPROBE-733 (JEOL, Japan, Palo Alto, CA) ...
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Modification of Co–Cr alloys to optimize additively welded
In this present work, the influence of adding small amounts of hafnium and zirconium to the microstructure of the CoCr26Ni9Mo5W alloy (hereinafter Co–Cr initial alloy) is investigated. Furthermore, the machinability depending on the alloy modification is studied and compared with a hybrid machining process in addition to the conventional …
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Composition and microstructure of zirconium and …
... Previously, three approaches have been proposed for the synthesis of hafnium and zirconium germanates [1,2, [8] [9] [10] [11]. The first of them is a co …
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Evolution laws of microstructures and mechanical …
Evolution laws of microstructures and mechanical properties during heat treatments for near-α high-temperature titanium alloys Xiaozhao Ma1), Zhilei Xiang ... tanium alloy through the substitution of zirconium (Zr) ele-ment by hafnium (Hf) element. Elongations are enhanced due to the inhibiting effect of Hf element for the precipitation of
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Zirconium and Hafnium
Literature Resources on Zirconium and Hafnium. Discovery and History. Occurrence. Commercial Deposits. General Properties and Applications of the Elements and some of their Alloys and Compounds. Applications of the Metals and their Alloys other than in the Nuclear and Chemical Industries. Safety Precautions
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Thermodynamic Assessment of the Ternary B-Hf-Zr …
Recently, HfB 2 and ZrB 2 composites prepared via in situ reactive sintering were reported to have high density, fine microstructures and excellent mechanical properties. ... Critical Assessment and Thermodynamic Calculation of the Ternary System C-Hf-Zr (Carbon-Zirconium-Hafnium), J. Phase Equilib., 2002, 23(3), p 218–235.
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The Role of Hafnium in Modern Thermal Barrier Coatings
The mixtures of zirconium–hafnium dioxides partially stabilized by Y 2 O 3 in harsh plasma spraying conditions create a pure metastable t′ phase, with the microstructure close to that of the t′-ZrO 2 phase. The stability of the t′ phase at elevated temperatures strongly depends on the ceramic chemical composition.
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The temperature-dependent fracture strength model for …
Breaking down the entire structure of a material implies severing all the bonds between its atoms either by applying work or by heat transfer. Because bond-breaking is indifferent to either means, there is a kind of equivalence between heat energy and strain energy. Based on this equivalence, we assume the existence of a constant …
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Development in the Production of Hafnium Wire Conforming …
With the steady increase in the number of nuclear reactors in Russia and around the world, the demand for this metal in the nuclear industry is growing [4,5,6,7,8].Hafnium is also used in electrical engineering, e.g., in cathode and oscillating tubes and as electrodes in rectifiers and high-pressure gas-discharge tubes …
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The influence of hafnium removal on the …
Abstract. The effects of hafnium removal on the sinterability, phase composition, and microstructural, mechanical, and electrical properties of 8YSZ (8 …
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Asm Handbook Vol. 9 | PDF | Microstructure
ASM International is pleased to publish a new edition of Metallography and Microstructures, Volume. 9 of the ASM Handbook series. Metallography is a longstanding core interest of ASM International. members, and this new …
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