We use room temperature ion beam assisted sputtering to deposit niobium nitride thin films. Study of nbn josephson junctions with a tantalum nitride. We have prepared an epitaxial niobium nitride nbn film and nbnalnnbn tunnel junctions to investigate the energy gaps. Critical assessment of the electrocatalytic activity of. Oct 21, 2017 we have measured the transmission spectra of the conventional bardeencooperschrieffer bcs superconductor niobium nitride nbn thin films t c 11 k using terahertz timedomain spectroscopy thztds over the spectral range of 10 110 cm. Pdf room temperature deposition of superconducting niobium. The superconducting energy gap a was measured by the electron tunneling method in niobium nitride having a columnar structure and a superconducting. Jul 15, 2015 herein, niobium nitride, nb 4 n 5, is explored to be an excellent capacitive material for the first time. Celebrated as one of the most fundamental results in experimental physics 1 1, the observation of this particle confirms the existence of the associated higgs field that plays a pivotal role in the standard model of particle physics.
At low temperatures about 16 k nbn, niobium nitride becomes a superconductor, and is used in detectors for infrared light uses. Hazra et al superconducting properties of very high quality nbn thin films grown by high temperature chemical vapor deposition supercond. Electrical and structural characterizations were performed by electric transport and magnetization measurements at variable temperatures, xray diffraction, and atomic force microscopy. Our materials are carefully handled to prevent damage during storage and transportation and to preserve the quality of our products in their original condition. By measuring the optical conductivity spectrum of a 41nmthick film with the critical temperature t c of about 14 k by terahertz timedomain spectroscopy, we obtained the gap frequency of about 1. Pdf on jan 10, 2018, jeanclaude villegier and others published refractory niobium nitride nbn josephson junctions and applications find, read and cite all the research you need on researchgate. Pdf niobium nitridebased normal metalinsulatorsuperconductor.
An illdefined gap was suggested due to the broadening of the onset. Tantalum nitride tan is a chemical compound, a nitride of tantalum. Tantalum nitrides are also used in thin film resistors. Reactive dc magnetron sputtering of ultrathin superconducting niobium nitride films by andrew e. The number of electrons in each of niobium s shells is 2, 8, 18, 12, 1 and its electron configuration is kr 4d 4 5s 1. Niobium nitride is a compound of niobium and nitrogen with the chemical formula nbn. Although this high value of the superconducting energy gap is promising for potential electronic.
This energy can be provided by a laser 26 or generated by an arc discharge 79. The combination of high t c and small coherence length. The full limiting value of the energy gap obtained is 2. Onodera research institute of electrical communication, tohoku university, sendai, japan received 17 october 1968 using the technique of electron tunneling between superconducting films, we have measured the energy gap of nbn. The augmentedplanewave method is applied to calculate the electronic band structure of niobium nitride nbn. Osa tuning of superconducting niobium nitride terahertz. Especially the latter is necessary for a longer cutoff wavelength but is often limited by inhomogeneities and constrictions in the active area of the detector 14, 18. Detectors based on it can detect a single photon in the 110 micrometer section of the infrared spectrum, which is important for. They are characterized using thz time domain spectroscopy over a temperature range from 8. Any material exhibiting these properties is a superconductor. The band structures and band ordering for nbc and nbn are seen to be very. Even though the substrates were not heated, the nbn films had excellent superconducting properties.
Nanowire singlephoton detectors made of atomic layerdeposited niobium nitride e knehr1,2, a kuzmin2, d yu vodolazov3,4, m ziegler1, s doerner2, k ilin2, m siegel2, r stolz1 and h schmidt1,5 1department of quantum detection, leibniz institute of photonic technology leibniz ipht, jena, germany 2institute of micro and nanoelectronic systems, karlsruhe institute of technology kit, karlsruhe. Electronic stiffness of a superconducting niobium nitride. Using variable angle spectral ellipsometry vase, i found that the optical properties of nbn films appear to have a critical thickness above which the optical parameters stabilize. Valence band of oxygens 2p orbital o2p vb is expressed by the occupied mos, while conduction band of titaniums 3d orbital ti3d cb is expressed by the unoccupied mos. Moreover, due to its enhanced t c with respect to niobium, nbn has a greater energy gap 2. Efficient immobilization and fast conversion of soluble lithium polysulfide intermediates lipss are crucial to the electrochemical performance of lis batteries. At low temperatures about 16 k nbn, niobium nitride becomes a superconductor, and is used in detectors for infrared light.
Superconducting properties and crystal structures of single. The dominant effect of pressure on n e is a broadening of the bands and the resulting decrease of n e in most energy regions. A codoped porous niobium nitride nanogrid as an effective. Introducing nitrogen to niobium decreases the mean free path and increases the energy gap. The recent discovery of the higgs boson has created a lot of excitement among scientists. Heats of formation of niobium nitride, tantalum nitride and.
K by terahertz timedomain spectroscopy, we obtained the gap frequency of about 1. Tuning of superconducting niobium nitride terahertz metamaterials. Nanowire singlephoton detectors made of atomic layer. We have studied the structural and electronic properties of niobium nitride and. Nb 2 n and the nitrogento niobium ratio was found to be in the range of 0. Fabrication of a superconducting niobium nitride hot. In the area of voltages v beyond the gap up to 30 mev, a complex structure is observed for the first time in graphs of dvdi and d 2 idv 2 as a function of v i is the current trough the tunnel junction. In this paper, we describe the preparation of a nbbased binary nitride material with a porous nanogrid mo. About niobium nitride sputtering target american elements specializes in producing high purity niobium nitride sputtering targets with the highest possible density and smallest possible average grain sizes for use in semiconductor, chemical vapor deposition cvd and physical vapor deposition pvd display and optical applications. Niobium nitride sputtering target american elements.
Conductive cobalt doped niobium nitride porous spheres as an efficient polysulfide convertor for advanced lithiumsulfur batteries weini ge, ad lu wang, a chuanchuan li, a chunsheng wang, a debao wang, b yitai qian a and liqiang xu ac. Niobium nitride nbn thin films have been deposited by reactive direct current magnetron sputtering at 0. Terahertz electrodynamics and superconducting energy gap. Magnetoresistance oscillations in granular superconducting niobium nitride nanowires u. Detectors based on it can detect a single photon in the 110 micrometer section of the infrared spectrum, 4 which is important for astronomy and telecommunications. Lithiumsulfur lis batteries are promising nextgeneration energy storage devices because of their high energy density of 2600 wh kg1. Conductive mesoporous niobium nitride microspheres. Reactive dc magnetron sputtering of ultrathin superconducting. Niobium nitride, in particular, is a promising material in this respect given its relatively high critical temperature and energy gap of the order, respectively, of 16 k and 2. Optical and tunneling studies of energy gap in superconducting. Previous theoretical work has predicted vanadium and niobium nitrides to be catalytically active toward the electrochemical reduction of dinitrogen to ammonia and inactive for the hydrogen evolution reaction. Pdf tuning of superconducting niobium nitride terahertz.
Using the technique of electron tunneling between superconducting films, we have measured the energy gap of nbn. In this thesis i made a study of the properties of reactively sputtered ultrathin films of niobium nitride nbn and niobium titanium nitride nbtin. Furthermore, the stem images and the corresponding energy dispersive xray spectroscopy maps of carbon c, nitrogen n, oxygen o and niobium nb are clearly observed in the fig 2dh and all of them display a similar distribution. Superconductivity is the set of physical properties observed in certain materials, wherein electrical resistance vanishes and from which magnetic flux fields are expelled. The table shows element percentages for nbn niobium nitride. Volume 28, issue 5, 16 december 1968, pages 335336. Structural and superconducting analyses of the films demonstrate that using mgo and al 2 o 3 substrates can significantly improve the film properties compared to. Fplapw investigations of electronic structure and bonding. Conductive cobalt doped niobium nitride porous spheres as. Synthesis and superconducting properties of niobium. We have measured the transmission spectra of the conventional bardeencooperschrieffer bcs superconductor niobium nitride nbn thin films t c 11 k using terahertz timedomain spectroscopy thztds over the spectral range of 10 110 cm.
Heats of formation of niobium nitride, tantalum nitride and zirconium nitride from combustion calorimetry alla d. Finally, superconducting detectors have been found to exhibit a large hardness to radiation aging 19. Very long single and fewwalled boron nitride nanotubes via. Over samples were deposited on a variety of substrates, under various chamber conditions. Niobium was discovered by charles hatchett in 1801 and first isolated by christian wilhelm blomstrand in 1864. Jul 31, 2011 the energy gap in the density of states survives across the transition, but coherence peaks exist only in the superconductor. Porous niobium nitride as a capacitive anode material for advanced liion hybrid capacitor with superior cycling stability peiyu wangab, rutao wanga, junwei langa, xu zhanga, zhenkun chena and xingbin yan, a a laboratory of clean energy chemistry and materials, state key laboratory of.
There are multiple phases of compounds, stoichimetrically from ta 2 n to ta 3 n 5 including tan as a thin film tan find use as a diffusion barrier and insulating layer between copper interconnects in the back end of line of computer chips. Niobium nitride nbnthin films thanks to their high tc. Dc reactive magnetron sputtering was used to deposit fewnanometerthick films of niobium nitride for fabrication of superconducting devices. The results suggested that the niobium nitride was crystalline in the single phase of hexagonal. In this process, titanium and niobium ions and atoms are detached from a fixed target by supplying electrical energy, ionized and accelerated onto the implant surface. Scoping studies of dopants for stabilization of uranium. The titanium niobium nitride surface is an additive technique by which the coating is firmly anchored in the implant surface. Transition metal nitrides have recently attracted significant interest as electrocatalysts for the oxygen reduction reaction orr owing to their low electrical resistance and good corrosion resistance. The transition temperature is appealing because of the progress achieved in closedcycle refrigeration, while the value of the gap is stimulating for engineering. Superconducting detectors and josephson readout circuits have also a low crosssection for more energetic photons and other particles, since they are composed of thin metallic layers deposited on intrinsic large energy gap, low loss substrates sapphire, mgo. Wed like to understand how you use our websites in order to improve them. Superconducting energy gap of niobium nitride jetp. Terahertz electrodynamics and superconducting energy gap of. Nanowire singlephoton detectors made of atomic layerdeposited niobium nitride e knehr1,2, a kuzmin2, d yu vodolazov3,4, m ziegler1, s doerner2, k ilin2, m siegel2, r stolz1 and h schmidt1,5 1department of quantum detection, leibniz institute of photonic technology leibniz ipht, jena, germany 2institute of micro and nanoelectronic systems, karlsruhe institute of technology kit.
Single and twoparticle energy gaps across the disorder. A decrease in bcs resistance is also observed from standard niobium while the residual resistance is comparable between doped and standard. St0214 niobium nitride nbn sputtering target global. The mean grain size of these nitrides was about 18 nm. Bnnts form when the liberated vapors react with nitrogen and condense into solid state. Magnetoresistance oscillations in granular superconducting niobium nitride nanowires. Terahertz electrodynamics and superconducting energy gap of nbn.
Fabrication of a superconducting niobium nitride hot electron. Unlike an ordinary metallic conductor, whose resistance decreases gradually as its temperature is lowered even down to near absolute zero, a superconductor has a. Scoping studies of dopants for stabilization of uranium nitride fuel klara insulander bjork, a aneta herman,b marcus hedberg,b and christian ekberg b achalmers university of technology, department of physics, division of subatomic and plasma physics, 412 96. Because of the higgs bosons large mass about 125 gev, it could. Room temperature deposition of superconducting niobium. Ultrathin niobium nitride films with thickness of 5 nm were deposited by sputtering niobium target by nitrogen ions on the oxidized 0. In this article, we describe the superconducting properties and crystal structure of the nbn films. Webelements periodic table niobium niobium nitride. Superconducting properties and crystal structures of. Structural, electronic, and mechanical properties of.
The peak of the density of states for the higher bands is at 2. Energy gap measurement of niobium nitride sciencedirect. Characterization of terahertz detectors based on niobium. Nbnalnnb tunnel junctions were fabricated to measure the superconducting energy gap of the nbn films. An illdefined gap was suggested due to the broadening of the. Abstract using the technique of electron tunneling between superconducting films, we have measured the energy gap of nbn. Xray diffraction characteristics xray diffraction patterns have shown that the niobium nitride layers in multilayers grown on both 101l2 sapphire. The pseudogap region in the disordered niobium nitride nbn superconductors has been a subject of contemporary interest and its existence for higher disorder films have been established. Superconducting properties of very high quality nbn thin. We manufacture and distribute sputtering targets and evaporation materials for all sputtering tools. Escamilla superconducting niobium nitride films deposited by unbalanced magnetron sputtering thin solid films vol.
The present experimental study investigates the electrocatalytic activity of vanadiumiii nitride, niobium iii nitride, and nb4n5 for the nitrogen reduction reaction in aqueous. Although this high value of the superconducting energy gap is promising for. Bandgap can be approximately estimated by the total energy difference between homo and lumo. Efficient polysulfide blocker from conductive niobium. Xray diffraction characteristics xray diffraction patterns have shown that the niobium nitride layers in. Since niobium nitride nbn stjs have nearly twice the energy gap of niobium, they may have good performance at relatively high temperatures.
Superior cycling stability material for advanced liion. Sam is specialized in supplying high quality niobium nitride nbn sputtering target. For this reason, it is believed that changes in bcs material properties are the driving force behind the q. Magnetoresistance oscillations in granular superconducting. Niobium nitride based normal metalinsulatorsuperconductor tunnel junction microthermometer. Nbn niobium nitride sputtering targets vacuum engineering. Herein, we report a novel strategy to simultaneously achieve large capacity, high. Electrodynamics of the superconducting state in ultrathin.