Development and Status of Tool Coating
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Thermodynamic Routes to Novel Metastable Nitrogen-Rich Nitrides
Article pubs.acs.org/cm Thermodynamic Routes to Novel Metastable Nitrogen-Rich Nitrides Wenhao Sun,†,‡ Aaron Holder,§,⊥ Bernardo Orvañanos,‡ Elisabetta Arca,§ Andriy Zakutayev,§ Stephan Lany,§ and Gerbrand Ceder*,†,‡,∥ † Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States ‡ Department of Materials Science and Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, United States § National Renewable Energy Laboratory, Golden, Colorado 80401, United States ∥ Department of Materials Science and Engineering, Univeristy of California, Berkeley, California 94720, United States ⊥ Department of Chemical and Biological Engineering, Univeristy of Colorado, Boulder, Colorado 80309, United States *S Supporting Information ABSTRACT: Compared to oxides, the nitrides are relatively unexplored, making them a promising chemical space for novel materials discovery. Of particular interest are nitrogen-rich nitrides, which often possess useful semiconducting properties for electronic and optoelectronic applications. However, such nitrogen-rich compounds are generally metastable, and the lack of a guiding theory for their synthesis has limited their exploration. Here, we review the remarkable metastability of observed nitrides, and examine the thermodynamics of how reactive nitrogen precursors can stabilize metastable nitrogen-rich compositions during materials synthesis. We map these thermodynamic strategies onto a predictive computational search, training a data-mined -
Effect of Nitrogen Pressure on the Structure of Cr-N, Ta-N, Mo-N, and WN Nanocrystals Synthesized by Arc Discharge
Hindawi Publishing Corporation Journal of Nanomaterials Volume 2011, Article ID 781935, 5 pages doi:10.1155/2011/781935 Research Article Effect of Nitrogen Pressure on the Structure of Cr-N, Ta-N, Mo-N, and W-N Nanocrystals Synthesized by Arc Discharge Longhai Shen and Nan Wang School of Science, Shenyang Ligong University, Shenyang 110159, China Correspondence should be addressed to Longhai Shen, [email protected] Received 28 March 2011; Revised 10 June 2011; Accepted 5 July 2011 Academic Editor: Theodorian Borca-Tasciuc Copyright © 2011 L. Shen and N. Wang. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. The effect of nitrogen pressure on the structure of Ta-N, Cr-N, Mo-N, and W-N nanocrystals formed in arc discharge process was investigated. At the nitrogen pressure of 5 ∼ 20 kPa, the pure cubic-phase TaN and CrN nanocrystals were formed, whereas pure cubic phase of Mo2N and W2N cannot be obtained. A little of metal Mo and a mass of metal W were mixed with the products of Mo2N and W2N, respectively. At the nitrogen pressure of 30 ∼ 50 kPa, subnitride Ta2NandCr2N and metal Cr were gradually formed in the product; furthermore, the proportion of metal Mo and W increased in the product of Mo2N and W2N, respectively. It indicated that the low nitrogen pressure makes cubic mononitride formation favorable. We explain this experimental observation in terms of the evaporation rate of anode metal and the ionization of nitrogen. -
Ultra-Thin Niobium Nitride Films for Hot Electron Bolometer and Thz Applications
THESIS FOR THE DEGREE OF LICENTIATE OF ENGINEERING Ultra-thin Niobium Nitride Films for Hot Electron Bolometer and THz Applications SASCHA KRAUSE Group for Advanced Receiver Development Department of Earth and Space Science CHALMERS UNIVERSITY OF TECHNOLOGY Gothenburg, Sweden 2016 i Ultra-thin Niobium Nitride Films for Hot Electron Bolometer and THz Applications SASCHA KRAUSE © SASCHA KRAUSE, 2016. Thesis for the degree of Licentiate of Engineering Group for Advanced Receiver Development Department of Earth and Space Science Chalmers University of Technology SE-412 96 Gothenburg Sweden Telephone + 46 (0)31-772 1000 Cover: Upper left corner: The Atacama Path Finder Experiment representing the exploration of space in the submillimeter and THz frequency range, upper right corner: HRTEM image of ultra-thin NbN film that is grown onto a GaN buffer-layer in an epitaxial manner, lower left corner: SEM image of the employed HEB used for measuring the phonon escape time, lower right corner: Resistance versus temperature behavior of the investigated ultra-thin NbN films which were grown onto different buffer-layers and substrates. [Printed by Chalmers Repro Service] Gothenburg, 2016 ii Ultra-thin Niobium Nitride Films for Hot Electron Bolometer and THz Applications SASCHA KRAUSE Group for Advanced Receiver Development Department of Earth and Space Science Chalmers University of Technology Gothenburg, Sweden 2016 Abstract The part of the electromagnetic spectrum between microwaves and infrared, also known as the terahertz band, is of particular interest for radio astronomy. The radiation intensity of the cold universe peaks at this frequency band, thus defining the demand on sensitive low-noise instruments in this particular frequency range. -
Development of a Nbn Deposition Process for Superconducting Quantum Sensors
1 Development of a NbN Deposition Process for Superconducting Quantum Sensors D. M. Glowacka, D. J. Goldie, S. Withington, H. Muhammad, G. Yassin , and B. K. Tan occurs with the addition of the reactive gas during sputtering, Abstract— We have carried out a detailed programme to which in turn affects stoichiometry. It is very important to explore the superconducting characteristics of reactive DC- quantify the location of the best operating point, and this magnetron sputtered NbN. The basic principle is to ignite a requires a careful study of the effects of deposition conditions. plasma using argon, and then to introduce a small additional Thakoor et al. [2] found that high-Tc NbN films were nitrogen flow to achieve the nitridation of a Nb target. Subsequent sputtering leads to the deposition of NbN onto the deposited at the point where the total sputter pressure started host substrate. The characteristics of a sputtered film depend on to increase rapidly with increasing nitrogen flow. In this paper, a number of parameters: argon pressure, nitrogen flow rate and we outline work that we have done to create a high-yield time-evolution profile, substrate material, etc. Crucially, the highly-reproducible deposition process for high-Tc NbN. We hysteresis in the target voltage as a function of the nitrogen flow also briefly describe work on realising and measuring can be used to provide a highly effective monitor of nitrogen resonators of the kind that would be suitable for a KID array consumption during the reactive process. By studying these dependencies we have been able to achieve highly reproducible operating at 3.5 K in an easy-to-use closed-cycle refrigerator. -
Enhancement of the Corrosion Resistance of 304 Stainless Steel by Cr–N and Cr(N,O) Coatings
Article Enhancement of the Corrosion Resistance of 304 Stainless Steel by Cr–N and Cr(N,O) Coatings Mihaela Dinu 1, Emile S. Massima Mouele 2, Anca C. Parau 1, Alina Vladescu 1,3, Leslie F. Petrik 2 and Mariana Braic 1,* 1 National Institute for Optoelectronics, 409 Atomistilor St., 077125 Magurele, Romania; [email protected] (M.D.); [email protected] (A.C.P.); [email protected] (A.V.) 2 Department of Chemistry, Environmental and Nano Sciences, University of the Western Cape, Robert Sobukwe Road, Bellville 7535, South Africa; [email protected] (E.S.M.M.); [email protected] (L.F.P.) 3 National Research Tomsk Polytechnic University, Lenin Avenue 43, Tomsk 634050, Russia * Correspondence: [email protected]; Tel.: +4-21-457-57-59 Received: 27 February 2018; Accepted: 2 April 2018; Published: 5 April 2018 Abstract: Chromium nitride and oxynitride coatings were deposited as monolayers ((Cr–N), Cr(N,O)) and bilayers (Cr–N/Cr(N,O), Cr(N,O)/Cr–N) on 304 steel substrates by reactive cathodic arc method. The coatings were characterised by X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive X-ray spectrometry (EDS), surface profilometry, and scratch tester. The anticorrosive properties of the coatings were assessed by electrochemical tests in 0.10 M NaCl + 1.96 M H2O2, carried out at 24 °C. Cr2N, CrN, and Cr(N,O) phases were identified in the coatings by grazing incidence X-ray diffraction (GI-XRD) measurements. The measured adhesion values ranged from 19 N to 35 N, the highest value being obtained for the bilayer with Cr(N,O) on top. -
Compound - Physical Properties Density Melting Point G Cm-3 C
Goodfellow Corporation 125 Hookstown Grade Road, Coraopolis, PA 15108-9302. USA Tel: 1-800-821-2870 : Fax 1-800-283-2020 Compound - Physical Properties Density Melting point g cm-3 C Aluminum Carbide 2.36 - Al C 4 3 Aluminum Nitride 3.26 - AlN Antimony Telluride 6.50 - Sb Te 2 3 Barium Titanate 5.8-6.0 - BaTiO3 Bismuth Telluride 7.7 - Bi Te 2 3 Boron Nitride 2.25 - BN Calcium Boride 2.3 - CaB6 Calcium Fluoride 3.18 1360-1400 CaF2 Calcium Titanate 4.10 1975 CaTiO3 Chromium Carbide 6.68 - Cr C 3 2 Chromium Diboride 4.36 - CrB2 Chromium Nitride 5.9 - Cr2N Chromium Silicide 5.5 - CrSi2 Cobalt (II) Oxide 6.45 1795 CoO Cobalt (III) Oxide 5.18 - Co O 3 4 Copper Selenide 5.99 - CuSe Cupric Oxide 6.39 - CuO Hafnium Carbide 12.2 approx. 3890 HfC Hafnium Diboride 10.5 3100 HfB2 Indium Oxide/Tin Oxide 7.16 - In O 90 /SnO2 10 2 3 All information and technical data are given as a guide only. Although every effort has been made to ensure that the information 1 is correct, no warranty is given as to its completeness or accuracy. September 17 2021 Goodfellow Corporation 125 Hookstown Grade Road, Coraopolis, PA 15108-9302. USA Tel: 1-800-821-2870 : Fax 1-800-283-2020 Compound - Physical Properties Density Melting point g cm-3 C Iron Silicide 6.1 - FeSi Lanthanum Hexaboride 2.61 - LaB6 Lead Selenide 8.10 - PbSe Magnesium Fluoride - 1396 MgF2 Magnesium Oxide 3.58 - MgO Molybdenum Carbide 8.9 - Mo2C Molybdenum Diboride 7.12 - MoB2 Molybdenum Disilicide 6.31 - MoSi2 Nickel Oxide 6.67 1984 NiO Niobium Boride 6.97 - NbB2 Niobium Carbide 7.6 - NbC Niobium Nitride 8.4 - NbN Niobium Pentoxide 4.47 - Nb O 2 5 Niobium Silicide 5.37 - NbSi2 Silicon Carbide 3.217 - SiC Silicon Monoxide 2.13 - SiO Silicon Nitride 3.44 - Si N 3 4 Silver Chloride 5.56 455 AgCl Sodium Chloride 2.16 - NaCl Tantalum Boride 11.15 approx. -
Novel Semiconductor-Superconductor Structure Features Versatile Gallium Nitride 8 March 2018, by Tom Fleischman
Novel semiconductor-superconductor structure features versatile gallium nitride 8 March 2018, by Tom Fleischman niobium nitride (NbN), a proven superconductor material used in quantum communications, astronomy and a host of other applications. The group's paper, "GaN/NbN Epitaxial Semiconductor/Superconductor Heterostructures," is being published online March 8 in Nature. Former postdoctoral researcher Rusen Yan and current postdoc Guru Khalsa are co-lead authors. Other key contributors were Grace Xing, the Bandgap, lattice constant, crystallinity and Richard Lundquist Sesquicentennial Professor in superconductivity in epitaxial NbNx on SiC. a, Bandgap ECE and MSE, and David Muller, the Samuel B. versus lattice constant for select nitride semiconductors as well as for SiC. b, Cross-section HAADFSTEM Eckert Professor of Engineering in the Department images in black/white (left) and false-colour (right) of of Applied and Engineering Physics. 5-nm NbNx grown on an SiC substrate with a AlN capping layer. c, Resistance versus temperature The method for combining the two materials – (normalized to the resistance at 16K), showing the molecular beam epitaxy (MBE), essentially spray superconducting phase transition of 5-nm (red) and painting of gallium and nitrogen atoms onto the 35-nm (blue) . Credit: Nature (2018). DOI: NbN in a vacuum environment – creates an 10.1038/nature25768 extremely clean interface and is key to the success of the novel structure. This advance, the group says, opens up a range of Silicon has been the semiconductor material of possibilities that can now combine the macroscopic choice for electronics pretty much since the quantum effects of superconductors with the rich transistor effect was first observed and identified electronic and photonic properties of group III- nearly 80 years ago. -
Discovery of Superconductivity in Hard Hexagonal Ε-Nbn
BNL-111904-2016-JA Discovery of Superconductivity in Hard Hexagonal ε-NbN Yongtao Zou1,2, Xintong Qi3, Cheng Zhang4, Shuailing Ma1, Wei Zhang5, Ying Li2, Ting Chen3, Xuebing Wang3, Zhiqiang Chen2, David Welch4,6, Pinwen Zhu1, Bingbing Liu1, Qiang Li4, Tian Cui1 & Baosheng Li2 1State Key Laboratory of Superhard Materials, College of Physics, Jilin University, Changchun, 130012, China. 2Mineral Physics Institute, State University of New York, Stony Brook, N.Y. 11794, United States. 3Department of Geosciences, State University of New York, Stony Brook, N.Y. 11794, United States. 4Condensed Matter Physics and Materials Science Department, Brookhaven National Laboratory, Upton, N.Y. 11973, United States. 5School of Science, Southwest University of Science and Technology, Mianyang, Sichuan 621010, China. 6Department of Materials Science and Engineering, State University of New York, Stony Brook, N.Y. 11794, United States. *Correspondence and requests for materials should be addressed to Y. Z. (E-mail: [email protected] ), Y. L . (E-mail:[email protected]) **The current ultrasonic, magnetization and electrical resistivity measurements were performed in the U. S. when Yongtao Zou was working at the State University of New York (Stony Brook). Since the discovery of superconductivity in boron-doped diamond with a critical temperature (TC) near 4 K, great interest has been attracted in hard superconductors such as transition-metal nitrides and carbides. Here we report the new discovery of superconductivity in polycrystalline hexagonal ε-NbN synthesized at high pressure and high temperature. Direct magnetization and electrical resistivity measurements demonstrate that the superconductivity in bulk polycrystalline hexagonal ε-NbN is below ~11.6 K, which is significantly higher than that for boron-doped diamond. -
Ligand-Based Reduction of CO2 to CO Mediated by an Anionic Niobium Nitride Complex
Ligand-Based Reduction of CO2 to CO Mediated by an Anionic Niobium Nitride Complex The MIT Faculty has made this article openly available. Please share how this access benefits you. Your story matters. Citation Silvia, Jared S., and Christopher C. Cummins. “Ligand-Based Reduction of CO2 to CO Mediated by an Anionic Niobium Nitride Complex.” Journal of the American Chemical Society 132.7 (2010) : 2169-2171. As Published http://dx.doi.org/10.1021/ja910445r Publisher American Chemical Society Version Author's final manuscript Citable link http://hdl.handle.net/1721.1/65162 Terms of Use Article is made available in accordance with the publisher's policy and may be subject to US copyright law. Please refer to the publisher's site for terms of use. Ligand-Based Reduction of CO2 to CO Mediated by an Anionic Niobium Nitride Complex Jared S. Silvia and Christopher C. Cummins Department of Chemistry, Massachusetts Institute of Technology, Cambridge, Massachusetts, 02139 RECEIVED DATE (automatically inserted by publisher); E-mail: [email protected] There are several motivations for producing chemicals from Scheme 1 CO2 whenever possible, and in particular, CO is a promising target being both a versatile chemical precursor and a fuel.1 Reducing metal complexes capable of O-atom abstraction from CO2 typically lead to the formation of strong metal- oxygen bonds that represent a challenge to catalytic turnover.2 In a special case for which the binding of CO2 evidently involves insertion into a Cu–B linkage, catalytic turnover producing CO was accomplished by taking advantage of the ultimate delivery of oxygen into a stable B–O–B reservoir.3 This is to be compared with electrocatalytic methods for CO2 reduction to CO in systems that likely involve a direct interaction between CO2 and the metal center at some point in the catalytic cycle.4 Another commonly observed trend in metal-mediated CO2 reduction is disproportionation reactivity 2– leading to the formation of CO and CO3 , highlighted by the reaction of Li2[W(CO)5] with CO2 to give W(CO)6 and 5 Li2CO3. -
Atom Transfer Reactions of High-Valent Chromium and Manganese Porphyrins James G
Iowa State University Capstones, Theses and Retrospective Theses and Dissertations Dissertations 1991 Atom transfer reactions of high-valent chromium and manganese porphyrins James G. Goll Iowa State University Follow this and additional works at: https://lib.dr.iastate.edu/rtd Part of the Inorganic Chemistry Commons Recommended Citation Goll, James G., "Atom transfer reactions of high-valent chromium and manganese porphyrins " (1991). Retrospective Theses and Dissertations. 10035. https://lib.dr.iastate.edu/rtd/10035 This Dissertation is brought to you for free and open access by the Iowa State University Capstones, Theses and Dissertations at Iowa State University Digital Repository. It has been accepted for inclusion in Retrospective Theses and Dissertations by an authorized administrator of Iowa State University Digital Repository. For more information, please contact [email protected]. INFORMATION TO USERS This manuscript has been reproduced from the microfihn master. UMI films the text directly from the original or copy submitted. Thus, some thesis and dissertation copies are in typewriter face, while others may be from any type of computer printer. The quality of this reproduction is dependent upon the quality of the copy submitted. Broken or indistinct print, colored or poor quality illustrations and photographs, print bleedthrough, substandard margins, and improper alignment can adversely affect reproduction. In the unlikely event that the author did not send UMI a complete manuscript and there are missing pages, these will be noted. Also, if unauthorized copyright material had to be removed, a note wiU indicate the deletion. Oversize materials (e.g., maps, drawings, charts) are reproduced by sectioning the original, beginning at the upper left-hand corner and continuing from left to right in equal sections with small overlaps. -
The Impact of Anionic Vacancies on the Mechanical Properties of Nbc and Nbn: an Ab Initio Study
The Impact of Anionic Vacancies on the Mechanical Properties of NbC and NbN: An ab initio Study P. W. Muchiria,c, K. K. Korirb,c, N. W. Makauc, G. O. Amoloa,c aMaterials Modeling Group, School of Physics and Earth Sciences, The Technical University of Kenya, P.O. Box, 52428-00200, Nairobi, Kenya. bPhysics Department, Moi University, P.O. Box, 3900-30100, Eldoret, Kenya. cComputational Material Science Group, Physics Department, University of Eldoret, P.O. Box, 1125-30100, Eldoret, Kenya. Abstract The development of super-hard materials has recently focused on systems containing heavy transition metal and light main group elements. Niobium carbides and nitrides have previously been identified as potential candidates, however, the volatility of carbon and nitrogen during synthesis make them prone to formation of anionic vacancies, which have the ability of changing the electronic structure, dynamical stability and adversely affecting the mechanical properties. Here, we present ab initio Density Functional Theory calculations that probe the occurrence of anionic vacancies as a function of concentration, thereafter, pertinent mechanical properties are investigated. Our results showed that the presence of anionic vacancies in NbC and NbN tend to deteriorate the mechanical properties and ultimately the mechanical hardness due to vacancy softening that can be attributed to defect induced covalent to metallic bond transition. Further, it was observed that anionic vacancies in NbC tend to modify its toughness, in particular, NbC in ZB becomes brittle while NbC in WZ becomes ductile in presences of C vacancies of up to 6%. On the other hand, the toughness of NbN was found to be insensitive to defect concentration of even up to 8%. -
Single-Photon Detection, Kinetic Inductance, and Non-Equilibrium Dynamics in Niobium and Niobium Nitride Superconducting Nanowires
Abstract Single-Photon Detection, Kinetic Inductance, and Non-Equilibrium Dynamics in Niobium and Niobium Nitride Superconducting Nanowires Anthony Joseph Annunziata 2010 This thesis is a study of superconducting niobium and niobium nitride nanowires used as single optical and near-infrared photon detectors. The nanowires are biased in the zero-voltage state with a current just below their critical current and at a temperature well below their critical temperature. In this state, an absorbed photon induces localized heating at the point of absorption. This suppresses the critical current in that location, creating a resistive region in the nanowire. The resistive region can grow under Joule heating and can self-reset to the zero-voltage state without the dc bias current being reduced. This study is twofold. First, niobium is investigated as an alternate detector material to niobium nitride. This study compares the performance niobium nanowire detectors of several geometries and fabricated in two different ways to the performance of niobium nitride nanowire detectors. Niobium detectors are found to have longer reset times and are more difficult to bias in a regime where they self-reset to the zero voltage state after detecting a photon. This makes niobium a less suitable material than niobium nitride for these detectors. In the second part of this study, the reset dynamics of these detectors are studied. Thermal relaxation is studied using a combination of experiments and numerical simulations. It is found that the thermal relaxation time for a niobium nanowire depends significantly on the amount of energy dissipated into the hotspot during the detection event.