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Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.

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At least 379 records · Page 21
All sourcesNASA NTRSDOE OSTI
NASA NTRS2004

Direct Electrolytic Deposition of Mats of Mn(x)O(y) Nanowires

Mats of free-standing manganese oxide (MnxOy) nanowires have been fabricated as experimental electrode materials for rechargeable electrochemical power cells and capacitors. Because they are free-standing, the wires in these mats are electrochemically accessible. The advantage of the mat-of-nanowires configuration, relative to other configurations of electrode materials, arises from the combination of narrowness and high areal number density of the wires. This combination offers both high surface areas for contact with electrolytes and short paths for diffusion of ions into and out of the electrodes, thereby making it possible to charge and discharge at rates higher than would otherwise be possible and, consequently, to achieve greater power densities. The nanowires are fabricated in an electrolytic process in which there is no need for an electrode binder material. Moreover, there is no need to incorporate an electrically conductive additive into the electrode material; the only electrically conductive material that must be added is a thin substrate contact film at the anchored ends of the nanowires. Hence, the mass fraction of active electrode material is close to 100 percent, as compared with about 85 percent in conventional electrodes made from a slurry of active electrode material, binder, and conductive additive pressed onto a metal foil. The locations and sizes of the nanowires are defined by holes in templates in the form of commercially available porous alumina membranes. In experiments to demonstrate the present process, alumina membranes of various pore sizes and degrees of porosity were used. First, a film of Au was sputtered onto one side of each membrane. The membranes were then attached, variously, to carbon tape or a gold substrate by use of silver or carbon paste. Once thus attached, the membranes were immersed in a plating solution comprising 0.01 M MnSO4 + 0.03 M (NH4)2SO4. The pH of the solution was kept constant at 8 by addition of H2SO4 or NH4OH as needed. Mn(x)O(y) nanowires were potentiostatically electrodeposited in the pores in the alumina templates. Depending on the anodic deposition potentials, Mn(x)O(y) was deposited in various oxidation states [divalent (Mn3O4), trivalent (Mn2O3), or tetravalent (MnO2)]. The Mn(x)O(y) wires were made free-standing (see figure) by dissolving the alumina templates, variously, in KOH or NaOH at a concentration of 20 volume percent.

Myung, Nosang↗
NASA NTRS2019

LCF Life of As-Deposited and Annealed NiCr-Y Coatings for Oxidation and Hot Corrosion Protection of Disk Alloys

Increasing temperatures in aero gas turbines is resulting in oxidation and hot corrosion attack of turbine disks. Since disks are sensitive to low cycle fatigue (LCF), any environmental attack, and especially hot corrosion pitting, can seriously degrade the life of the disk. Application of metallic coatings is one means of protecting disk alloys from this environmental attack. However, the presence of a metallic coating can degrade the LCF life of a disk alloy. Therefore, coatings must be designed which are not only resistant to oxidation and corrosion attack, but do not significantly degrade the LCF life of the alloy.Three different NiCr-Y coating compositions (29, 35.5, 44 wt.% Cr, all with 0.1 wt.% Y) were applied at two thicknesses by Plasma Enhanced Magnetron Sputtering (PEMS) to two similar Ni-based disk alloys. One Ni-35.5Cr-0.1Y coating also received a thin ZrO2 overcoat. The coated samples were also given a short thermal anneal in a low PO2 environment to encourage bonding of the coating and substrate as well as initiating formation of a chromia scale. Without further environmental exposure, the LCF life of coated and uncoated samples was evaluated at 760°C in air. The LCF lifetime of all coated samples was less than that of uncoated samples. The LCF life scaled with the Cr content and the high-Cr, thin coating showed the highest LCF life. Pre and post-test characterization of the various coatings, including identification of crack initiation sites, will be presented and the effect of the coating on the LCF life discussed.

low cycle fatigue↗
DOE OSTI2020

Materials Data on Y(BRu)4 by Materials Project

Y(RuB)4 crystallizes in the tetragonal I4_1/acd space group. The structure is three-dimensional. Y3+ is bonded in a 12-coordinate geometry to twelve equivalent B3- atoms. There are a spread of Y–B bond distances ranging from 2.97–3.22 Å. Ru+2.25+ is bonded to five equivalent B3- atoms to form a mixture of distorted edge and corner-sharing RuB5 trigonal bipyramids. There are a spread of Ru–B bond distances ranging from 2.15–2.29 Å. B3- is bonded in a 6-coordinate geometry to three equivalent Y3+, five equivalent Ru+2.25+, and one B3- atom. The B–B bond length is 1.80 Å.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Y(CuO2)2 by Materials Project

(CuO2)(Y)(CuO2) crystallizes in the monoclinic C2/c space group. The structure is three-dimensional. Y3+ is bonded in a 8-coordinate geometry to eight O2- atoms. There are a spread of Y–O bond distances ranging from 2.39–2.41 Å. There are two inequivalent Cu+2.50+ sites. In the first Cu+2.50+ site, Cu+2.50+ is bonded in a square co-planar geometry to four O2- atoms. There is two shorter (1.90 Å) and two longer (1.92 Å) Cu–O bond length. In the second Cu+2.50+ site, Cu+2.50+ is bonded in a square co-planar geometry to four O2- atoms. There is two shorter (1.90 Å) and two longer (1.91 Å) Cu–O bond length. There are two inequivalent O2- sites. In the first O2- site, O2- is bonded to two equivalent Y3+ and two Cu+2.50+ atoms to form a mixture of distorted corner and edge-sharing OY2Cu2 tetrahedra. In the second O2- site, O2- is bonded to two equivalent Y3+ and two Cu+2.50+ atoms to form a mixture of distorted corner and edge-sharing OY2Cu2 tetrahedra.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Y(HO)3 by Materials Project

Y(OH)3 crystallizes in the hexagonal P6_3/m space group. The structure is three-dimensional. Y3+ is bonded in a 9-coordinate geometry to nine equivalent O2- atoms. There are six shorter (2.43 Å) and three longer (2.49 Å) Y–O bond lengths. H1+ is bonded in a single-bond geometry to one O2- atom. The H–O bond length is 0.97 Å. O2- is bonded in a single-bond geometry to three equivalent Y3+ and one H1+ atom.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Y(CuSi)2 by Materials Project

Y(CuSi)2 crystallizes in the tetragonal I4/mmm space group. The structure is three-dimensional. Y3+ is bonded in a distorted body-centered cubic geometry to eight equivalent Si4- atoms. All Y–Si bond lengths are 3.05 Å. Cu+2.50+ is bonded to four equivalent Si4- atoms to form a mixture of edge and corner-sharing CuSi4 tetrahedra. All Cu–Si bond lengths are 2.38 Å. Si4- is bonded in a 9-coordinate geometry to four equivalent Y3+, four equivalent Cu+2.50+, and one Si4- atom. The Si–Si bond length is 2.35 Å.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Y(CrSi)2 by Materials Project

Y(CrSi)2 crystallizes in the tetragonal I4/mmm space group. The structure is three-dimensional. Y3+ is bonded in a body-centered cubic geometry to eight equivalent Si4- atoms. All Y–Si bond lengths are 2.99 Å. Cr+2.50+ is bonded to four equivalent Si4- atoms to form a mixture of corner and edge-sharing CrSi4 tetrahedra. All Cr–Si bond lengths are 2.40 Å. Si4- is bonded in a 9-coordinate geometry to four equivalent Y3+, four equivalent Cr+2.50+, and one Si4- atom. The Si–Si bond length is 2.47 Å.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Y(CoSi)2 by Materials Project

Y(CoSi)2 crystallizes in the tetragonal I4/mmm space group. The structure is three-dimensional. Y3+ is bonded in a distorted body-centered cubic geometry to eight equivalent Si4- atoms. All Y–Si bond lengths are 3.02 Å. Co+2.50+ is bonded to four equivalent Si4- atoms to form a mixture of corner and edge-sharing CoSi4 tetrahedra. All Co–Si bond lengths are 2.28 Å. Si4- is bonded in a 9-coordinate geometry to four equivalent Y3+, four equivalent Co+2.50+, and one Si4- atom. The Si–Si bond length is 2.51 Å.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Y(SiNi)2 by Materials Project

Y(NiSi)2 crystallizes in the tetragonal I4/mmm space group. The structure is three-dimensional. Y3+ is bonded in a distorted body-centered cubic geometry to eight equivalent Si4- atoms. All Y–Si bond lengths are 3.05 Å. Ni+2.50+ is bonded to four equivalent Si4- atoms to form a mixture of corner and edge-sharing NiSi4 tetrahedra. All Ni–Si bond lengths are 2.31 Å. Si4- is bonded in a 9-coordinate geometry to four equivalent Y3+, four equivalent Ni+2.50+, and one Si4- atom. The Si–Si bond length is 2.42 Å.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Y(IO3)3 by Materials Project

Y(O3I)3 crystallizes in the monoclinic P2_1/c space group. The structure is three-dimensional. Y3+ is bonded in a 8-coordinate geometry to eight O2- atoms. There are a spread of Y–O bond distances ranging from 2.27–2.61 Å. There are nine inequivalent O2- sites. In the first O2- site, O2- is bonded in a distorted bent 120 degrees geometry to one Y3+ and one I5+ atom. The O–I bond length is 1.83 Å. In the second O2- site, O2- is bonded in a 1-coordinate geometry to one Y3+ and one I5+ atom. The O–I bond length is 1.82 Å. In the third O2- site, O2- is bonded in a distorted bent 150 degrees geometry to one Y3+ and one I5+ atom. The O–I bond length is 1.84 Å. In the fourth O2- site, O2- is bonded in a distorted single-bond geometry to one I5+ atom. The O–I bond length is 1.83 Å. In the fifth O2- site, O2- is bonded in a bent 150 degrees geometry to one Y3+ and one I5+ atom. The O–I bond length is 1.81 Å. In the sixth O2- site, O2- is bonded in a 2-coordinate geometry to one Y3+ and one I5+ atom. The O–I bond length is 1.83 Å. In the seventh O2- site, O2- is bonded in a bent 150 degrees geometry to one Y3+ and one I5+ atom. The O–I bond length is 1.83 Å. In the eighth O2- site, O2- is bonded in a distorted bent 120 degrees geometry to one Y3+ and one I5+ atom. The O–I bond length is 1.85 Å. In the ninth O2- site, O2- is bonded in a distorted bent 150 degrees geometry to one Y3+ and one I5+ atom. The O–I bond length is 1.83 Å. There are three inequivalent I5+ sites. In the first I5+ site, I5+ is bonded in a 3-coordinate geometry to three O2- atoms. In the second I5+ site, I5+ is bonded in a 3-coordinate geometry to three O2- atoms. In the third I5+ site, I5+ is bonded in a distorted trigonal non-coplanar geometry to three O2- atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Y(BH4)3 by Materials Project

Y(BH4)3 crystallizes in the cubic Pa-3 space group. The structure is three-dimensional. Y3+ is bonded in a distorted q6 geometry to twelve H+0.50+ atoms. There are a spread of Y–H bond distances ranging from 2.28–2.35 Å. B3- is bonded in a tetrahedral geometry to four H+0.50+ atoms. All B–H bond lengths are 1.23 Å. There are four inequivalent H+0.50+ sites. In the first H+0.50+ site, H+0.50+ is bonded in a distorted single-bond geometry to one Y3+ and one B3- atom. In the second H+0.50+ site, H+0.50+ is bonded in a distorted single-bond geometry to one Y3+ and one B3- atom. In the third H+0.50+ site, H+0.50+ is bonded in a distorted single-bond geometry to one Y3+ and one B3- atom. In the fourth H+0.50+ site, H+0.50+ is bonded in a distorted single-bond geometry to one Y3+ and one B3- atom.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Y(SiOs)2 by Materials Project

Y(OsSi)2 crystallizes in the tetragonal I4/mmm space group. The structure is three-dimensional. Y3+ is bonded in a 8-coordinate geometry to eight equivalent Os+1.50- atoms. All Y–Os bond lengths are 3.19 Å. Os+1.50- is bonded in a 4-coordinate geometry to four equivalent Y3+ and four equivalent Si atoms. All Os–Si bond lengths are 2.40 Å. Si is bonded in a 5-coordinate geometry to four equivalent Os+1.50- and one Si atom. The Si–Si bond length is 2.49 Å.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Y(SiAu)2 by Materials Project

Y(AuSi)2 crystallizes in the tetragonal I4/mmm space group. The structure is three-dimensional. Y3+ is bonded to eight equivalent Si4- atoms to form YSi8 hexagonal bipyramids that share corners with sixteen equivalent AuSi4 tetrahedra, edges with four equivalent YSi8 hexagonal bipyramids, edges with eight equivalent AuSi4 tetrahedra, and faces with four equivalent YSi8 hexagonal bipyramids. All Y–Si bond lengths are 3.23 Å. Au+2.50+ is bonded to four equivalent Si4- atoms to form AuSi4 tetrahedra that share corners with eight equivalent YSi8 hexagonal bipyramids, corners with four equivalent AuSi4 tetrahedra, edges with four equivalent YSi8 hexagonal bipyramids, and edges with four equivalent AuSi4 tetrahedra. All Au–Si bond lengths are 2.57 Å. Si4- is bonded in a 9-coordinate geometry to four equivalent Y3+, four equivalent Au+2.50+, and one Si4- atom. The Si–Si bond length is 2.30 Å.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Y(HO)3 by Materials Project

Y(OH)3 crystallizes in the hexagonal P6_3 space group. The structure is three-dimensional. Y3+ is bonded in a 9-coordinate geometry to nine equivalent O2- atoms. There are a spread of Y–O bond distances ranging from 2.41–2.50 Å. H1+ is bonded in a single-bond geometry to one O2- atom. The H–O bond length is 0.97 Å. O2- is bonded in a single-bond geometry to three equivalent Y3+ and one H1+ atom.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Y(BO2)3 by Materials Project

Y(BO2)3 crystallizes in the monoclinic C2/c space group. The structure is three-dimensional. Y3+ is bonded in a 2-coordinate geometry to ten O2- atoms. There are a spread of Y–O bond distances ranging from 2.29–2.76 Å. There are two inequivalent B3+ sites. In the first B3+ site, B3+ is bonded in a tetrahedral geometry to four O2- atoms. There is two shorter (1.46 Å) and two longer (1.49 Å) B–O bond length. In the second B3+ site, B3+ is bonded in a trigonal planar geometry to three O2- atoms. There are a spread of B–O bond distances ranging from 1.34–1.42 Å. There are three inequivalent O2- sites. In the first O2- site, O2- is bonded in a 2-coordinate geometry to one Y3+ and two B3+ atoms. In the second O2- site, O2- is bonded in a distorted bent 120 degrees geometry to two equivalent Y3+ and two B3+ atoms. In the third O2- site, O2- is bonded in a 1-coordinate geometry to two equivalent Y3+ and one B3+ atom.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Y(BO2)3 by Materials Project

Y(BO2)3 crystallizes in the orthorhombic Pca2_1 space group. The structure is three-dimensional. Y3+ is bonded in a 6-coordinate geometry to six O2- atoms. There are a spread of Y–O bond distances ranging from 2.30–2.52 Å. There are three inequivalent B3+ sites. In the first B3+ site, B3+ is bonded to four O2- atoms to form corner-sharing BO4 tetrahedra. There are a spread of B–O bond distances ranging from 1.43–1.56 Å. In the second B3+ site, B3+ is bonded to four O2- atoms to form corner-sharing BO4 tetrahedra. There is three shorter (1.46 Å) and one longer (1.55 Å) B–O bond length. In the third B3+ site, B3+ is bonded to four O2- atoms to form corner-sharing BO4 tetrahedra. There are a spread of B–O bond distances ranging from 1.45–1.50 Å. There are six inequivalent O2- sites. In the first O2- site, O2- is bonded in a trigonal planar geometry to three B3+ atoms. In the second O2- site, O2- is bonded in a distorted bent 120 degrees geometry to one Y3+ and two B3+ atoms. In the third O2- site, O2- is bonded in a bent 120 degrees geometry to two B3+ atoms. In the fourth O2- site, O2- is bonded in a distorted bent 120 degrees geometry to one Y3+ and two B3+ atoms. In the fifth O2- site, O2- is bonded in a distorted single-bond geometry to three equivalent Y3+ and one B3+ atom. In the sixth O2- site, O2- is bonded in a distorted bent 120 degrees geometry to one Y3+ and two equivalent B3+ atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Y(Bi3O5)4 by Materials Project

Y(Bi3O5)4 crystallizes in the cubic I23 space group. The structure is three-dimensional. Y3+ is bonded to four equivalent O2- atoms to form YO4 tetrahedra that share corners with twelve equivalent BiO5 square pyramids. All Y–O bond lengths are 2.19 Å. Bi+3.08+ is bonded to five O2- atoms to form distorted BiO5 square pyramids that share corners with eight equivalent BiO5 square pyramids, a cornercorner with one YO4 tetrahedra, and an edgeedge with one BiO5 square pyramid. There are a spread of Bi–O bond distances ranging from 2.11–2.54 Å. There are three inequivalent O2- sites. In the first O2- site, O2- is bonded in a trigonal planar geometry to three equivalent Bi+3.08+ atoms. In the second O2- site, O2- is bonded in a distorted trigonal non-coplanar geometry to three equivalent Bi+3.08+ atoms. In the third O2- site, O2- is bonded to one Y3+ and three equivalent Bi+3.08+ atoms to form corner-sharing OYBi3 tetrahedra.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Y(NiO2)2 by Materials Project

Y(NiO2)2 is Spinel structured and crystallizes in the trigonal R-3m space group. The structure is three-dimensional. Y3+ is bonded to four O2- atoms to form YO4 tetrahedra that share corners with twelve NiO6 octahedra. The corner-sharing octahedral tilt angles are 60°. There are one shorter (2.13 Å) and three longer (2.14 Å) Y–O bond lengths. There are two inequivalent Ni+2.50+ sites. In the first Ni+2.50+ site, Ni+2.50+ is bonded to six O2- atoms to form NiO6 octahedra that share corners with six equivalent YO4 tetrahedra and edges with six NiO6 octahedra. There are four shorter (2.05 Å) and two longer (2.08 Å) Ni–O bond lengths. In the second Ni+2.50+ site, Ni+2.50+ is bonded to six equivalent O2- atoms to form NiO6 octahedra that share corners with six equivalent YO4 tetrahedra and edges with six equivalent NiO6 octahedra. All Ni–O bond lengths are 2.07 Å. There are two inequivalent O2- sites. In the first O2- site, O2- is bonded to one Y3+ and three Ni+2.50+ atoms to form a mixture of distorted edge and corner-sharing OYNi3 tetrahedra. In the second O2- site, O2- is bonded to one Y3+ and three equivalent Ni+2.50+ atoms to form a mixture of distorted edge and corner-sharing OYNi3 tetrahedra.

36 MATERIALS SCIENCE↗