Search NASA⌕ Search

SEARCH · Search NASA

Results for “Zircon group”

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.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 127 records · Page 7
All sourcesNASA NTRSDOE OSTI
DOE OSTI2020

Materials Data on PrPO4 by Materials Project

PrPO4 is Zircon structured and crystallizes in the tetragonal I4_1/amd space group. The structure is three-dimensional. Pr3+ is bonded in a 8-coordinate geometry to eight equivalent O2- atoms. There are four shorter (2.46 Å) and four longer (2.50 Å) Pr–O bond lengths. P5+ is bonded in a tetrahedral geometry to four equivalent O2- atoms. All P–O bond lengths are 1.56 Å. O2- is bonded in a 1-coordinate geometry to two equivalent Pr3+ and one P5+ atom.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Gd3Si2BrO8 by Materials Project

Gd3Si2O8Br is Zircon-derived structured and crystallizes in the orthorhombic Ima2 space group. The structure is three-dimensional. there are two inequivalent Gd3+ sites. In the first Gd3+ site, Gd3+ is bonded in a 8-coordinate geometry to seven O2- and one Br1- atom. There are a spread of Gd–O bond distances ranging from 2.26–2.81 Å. The Gd–Br bond length is 3.06 Å. In the second Gd3+ site, Gd3+ is bonded in a 8-coordinate geometry to six O2- and two equivalent Br1- atoms. There are a spread of Gd–O bond distances ranging from 2.33–2.73 Å. There are one shorter (2.96 Å) and one longer (3.00 Å) Gd–Br bond lengths. Si4+ is bonded in a tetrahedral geometry to four O2- atoms. There are a spread of Si–O bond distances ranging from 1.63–1.68 Å. There are four inequivalent O2- sites. In the first O2- site, O2- is bonded in a 1-coordinate geometry to two equivalent Gd3+ and one Si4+ atom. In the second O2- site, O2- is bonded in a 3-coordinate geometry to two equivalent Gd3+ and one Si4+ atom. In the third O2- site, O2- is bonded in a 1-coordinate geometry to three Gd3+ and one Si4+ atom. In the fourth O2- site, O2- is bonded in a 1-coordinate geometry to three Gd3+ and one Si4+ atom. Br1- is bonded in a 4-coordinate geometry to four Gd3+ atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on CaCd(WO4)2 by Materials Project

CaCd(WO4)2 is Zircon-derived structured and crystallizes in the monoclinic C2 space group. The structure is three-dimensional. Ca2+ is bonded in a 8-coordinate geometry to eight O2- atoms. There are a spread of Ca–O bond distances ranging from 2.43–2.51 Å. There are two inequivalent W6+ sites. In the first W6+ site, W6+ is bonded in a tetrahedral geometry to four O2- atoms. All W–O bond lengths are 1.83 Å. In the second W6+ site, W6+ is bonded in a tetrahedral geometry to four O2- atoms. All W–O bond lengths are 1.83 Å. Cd2+ is bonded in a 8-coordinate geometry to eight O2- atoms. There are a spread of Cd–O bond distances ranging from 2.42–2.51 Å. There are four inequivalent O2- sites. In the first O2- site, O2- is bonded in a distorted trigonal planar geometry to one Ca2+, one W6+, and one Cd2+ atom. In the second O2- site, O2- is bonded in a 3-coordinate geometry to one Ca2+, one W6+, and one Cd2+ atom. In the third O2- site, O2- is bonded in a 3-coordinate geometry to one Ca2+, one W6+, and one Cd2+ atom. In the fourth O2- site, O2- is bonded in a distorted trigonal planar geometry to one Ca2+, one W6+, and one Cd2+ atom.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Gd3YV4O16 by Materials Project

Gd3YV4O16 is Zircon-derived structured and crystallizes in the orthorhombic C222 space group. The structure is three-dimensional. there are two inequivalent Gd3+ sites. In the first Gd3+ site, Gd3+ is bonded in a 8-coordinate geometry to eight O2- atoms. There are four shorter (2.36 Å) and four longer (2.48 Å) Gd–O bond lengths. In the second Gd3+ site, Gd3+ is bonded in a 8-coordinate geometry to eight O2- atoms. There are a spread of Gd–O bond distances ranging from 2.35–2.49 Å. Y3+ is bonded in a 8-coordinate geometry to eight O2- atoms. There are four shorter (2.33 Å) and four longer (2.47 Å) Y–O bond lengths. There are three inequivalent V5+ sites. In the first V5+ site, V5+ is bonded in a tetrahedral geometry to four O2- atoms. All V–O bond lengths are 1.74 Å. In the second V5+ site, V5+ is bonded in a tetrahedral geometry to four equivalent O2- atoms. All V–O bond lengths are 1.74 Å. In the third V5+ site, V5+ is bonded in a tetrahedral geometry to four equivalent O2- atoms. All V–O bond lengths are 1.74 Å. There are four inequivalent O2- sites. In the first O2- site, O2- is bonded in a 1-coordinate geometry to one Gd3+, one Y3+, and one V5+ atom. In the second O2- site, O2- is bonded in a 1-coordinate geometry to two Gd3+ and one V5+ atom. In the third O2- site, O2- is bonded in a 1-coordinate geometry to one Gd3+, one Y3+, and one V5+ atom. In the fourth O2- site, O2- is bonded in a 1-coordinate geometry to two Gd3+ and one V5+ atom.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on KSm(MoO4)2 by Materials Project

KSm(MoO4)2 is Zircon-derived structured and crystallizes in the monoclinic C2 space group. The structure is three-dimensional. K1+ is bonded in a 8-coordinate geometry to eight O2- atoms. There are a spread of K–O bond distances ranging from 2.67–2.69 Å. Sm3+ is bonded in a 8-coordinate geometry to eight O2- atoms. There are four shorter (2.49 Å) and four longer (2.50 Å) Sm–O bond lengths. There are two inequivalent Mo6+ sites. In the first Mo6+ site, Mo6+ is bonded in a tetrahedral geometry to four O2- atoms. All Mo–O bond lengths are 1.81 Å. In the second Mo6+ site, Mo6+ is bonded in a tetrahedral geometry to four O2- atoms. There is two shorter (1.80 Å) and two longer (1.81 Å) Mo–O bond length. There are four inequivalent O2- sites. In the first O2- site, O2- is bonded in a 1-coordinate geometry to one K1+, one Sm3+, and one Mo6+ atom. In the second O2- site, O2- is bonded in a 3-coordinate geometry to one K1+, one Sm3+, and one Mo6+ atom. In the third O2- site, O2- is bonded in a 3-coordinate geometry to one K1+, one Sm3+, and one Mo6+ atom. In the fourth O2- site, O2- is bonded in a 1-coordinate geometry to one K1+, one Sm3+, and one Mo6+ atom.

36 MATERIALS SCIENCE↗
NASA NTRS2012

U-Pb Dating of Zircons and Phosphates in Lunar Meteorites, Acapulcoites and Angrites

Zircon U-Pb geochronology has made a great contribution to the timing of magmatism in the early Solar System [1-3]. Ca phosphates are another group of common accessory minerals in meteorites with great potential for U-Pb geochronology. Compared to zircons, the lower closure temperatures of the U-Pb system for apatite and merrillite (the most common phosphates in achondrites) makes them susceptible to resetting during thermal metamorphism. The different closure temperatures of the U-Pb system for zircon and apatite provide us an opportunity to discover the evolutionary history of meteoritic parent bodies, such as the crystallization ages of magmatism, as well as later impact events and thermal metamorphism. We have developed techniques using the Cameca IMS-1280 ion microprobe to date both zircon and phosphate grains in meteorites. Here we report U-Pb dating results for zircons and phosphates from lunar meteorites Dhofar 1442 and SaU 169. To test and verify the reliability of the newly developed phosphate dating technique, two additional meteorites, Acapulco, obtained from Acapulco consortium, and angrite NWA 4590 were also selected for this study as both have precisely known phosphate U-Pb ages by TIMS [4,5]. Both meteorites are from very fast cooled parent bodies with no sign of resetting [4,5], satisfying a necessity for precise dating.

Zhou, Q.↗
DOE OSTI2020

Ion beam irradiation of ABO4 compounds with the fergusonite, monazite, scheelite, and zircon structures

The effects of irradiation on CaWO4, SrWO4, BaWO4, YVO4, LaVO4, YNbO4, and LaNbO4 were investigated on thin crystals using 1.0 MeV Kr ions at 50-1000 K. All of the ABO4 compounds can be amorphized with calculated damage cross sections (σa = 1/Fc0) in the range of ~0.30-1.09 × 10-14 cm2 ion-1 at zero Kelvin. The analysis of fluence-temperature data returned critical temperatures for amorphization (Tc) of 311 ± 1, 358 ± 90, 325 ± 19, 415 ± 17, 541 ± 6, 636 ± 26, and 1012 ± 1 K, respectively, for the compounds listed above. Compared with previous in situ irradiation of ABO4 orthophosphate samples using 0.8 MeV Kr ions, the Tc values of LaVO4 and YVO4 are higher than those of LaPO4 and YPO4 by 82 K and 124 K, respectively. The Tc values of the three scheelite structures, CaWO4, SrWO4, and BaWO4, indicate that they are the most radiation tolerant compounds under these conditions. The A-B cation anti-site energies, EfAB, determined by DFT range from 2.48 to 10.58 eV and are highly correlated with the A-B cation ionic radius ratio, rA/rB, but are not correlated with Tc across the different structure types, suggesting that the formation and migration energies of Frenkel defects play a more important role in damage recovery in these compounds. We also discuss the role of cation and anion charge/iconicity as determined by DFT. ABO4 compounds with the zircon structure and B = P or V have a distinct advantage over those with B = Si as the damaged regions do not appear to be significantly affected by polymerization of (PO4) 3- or (VO4) 3- groups which might stabilize the amorphous fraction and ultimately lead to phase separation as observed in zircon (ZrSiO4).

amorphization↗
DOE OSTI2020

Materials Data on ZrSiO4 by Materials Project

ZrSiO4 is Zircon-like structured and crystallizes in the tetragonal I4_1/a space group. The structure is three-dimensional. Zr4+ is bonded in a 8-coordinate geometry to eight equivalent O2- atoms. There are four shorter (2.17 Å) and four longer (2.30 Å) Zr–O bond lengths. Si4+ is bonded in a tetrahedral geometry to four equivalent O2- atoms. All Si–O bond lengths are 1.67 Å. O2- is bonded in a 3-coordinate geometry to two equivalent Zr4+ and one Si4+ atom.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on LiYbF4 by Materials Project

LiYbF4 is Zircon-like structured and crystallizes in the tetragonal I4_1/a space group. The structure is three-dimensional. Li1+ is bonded in a 4-coordinate geometry to four equivalent F1- atoms. All Li–F bond lengths are 1.94 Å. Yb3+ is bonded in a 8-coordinate geometry to eight equivalent F1- atoms. All Yb–F bond lengths are 2.30 Å. F1- is bonded in a 3-coordinate geometry to one Li1+ and two equivalent Yb3+ atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on SmAsO4 by Materials Project

SmAsO4 is Zircon-like structured and crystallizes in the tetragonal I4_1/a space group. The structure is three-dimensional. Sm3+ is bonded in a 8-coordinate geometry to eight equivalent O2- atoms. There are four shorter (2.42 Å) and four longer (2.48 Å) Sm–O bond lengths. As5+ is bonded in a tetrahedral geometry to four equivalent O2- atoms. All As–O bond lengths are 1.73 Å. O2- is bonded in a 3-coordinate geometry to two equivalent Sm3+ and one As5+ atom.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on NdPO4 by Materials Project

NdPO4 is Zircon-like structured and crystallizes in the hexagonal P6_222 space group. The structure is three-dimensional. Nd3+ is bonded to eight equivalent O2- atoms to form distorted NdO8 hexagonal bipyramids that share corners with four equivalent PO4 tetrahedra, edges with four equivalent NdO8 hexagonal bipyramids, and edges with two equivalent PO4 tetrahedra. There are four shorter (2.43 Å) and four longer (2.56 Å) Nd–O bond lengths. P5+ is bonded to four equivalent O2- atoms to form PO4 tetrahedra that share corners with four equivalent NdO8 hexagonal bipyramids and edges with two equivalent NdO8 hexagonal bipyramids. All P–O bond lengths are 1.55 Å. O2- is bonded in a 1-coordinate geometry to two equivalent Nd3+ and one P5+ atom.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Li2CaHfF8 by Materials Project

Li2CaHfF8 is Zircon-derived structured and crystallizes in the tetragonal I-4 space group. The structure is three-dimensional. there are two inequivalent Li1+ sites. In the first Li1+ site, Li1+ is bonded in a distorted trigonal pyramidal geometry to four equivalent F1- atoms. All Li–F bond lengths are 1.93 Å. In the second Li1+ site, Li1+ is bonded in a tetrahedral geometry to four equivalent F1- atoms. All Li–F bond lengths are 1.94 Å. Ca2+ is bonded in a 8-coordinate geometry to eight F1- atoms. There are four shorter (2.32 Å) and four longer (2.41 Å) Ca–F bond lengths. Hf4+ is bonded in a 8-coordinate geometry to eight F1- atoms. There are four shorter (2.09 Å) and four longer (2.16 Å) Hf–F bond lengths. There are two inequivalent F1- sites. In the first F1- site, F1- is bonded in a distorted trigonal planar geometry to one Li1+, one Ca2+, and one Hf4+ atom. In the second F1- site, F1- is bonded in a distorted trigonal planar geometry to one Li1+, one Ca2+, and one Hf4+ atom.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on HoPS4 by Materials Project

HoPS4 is Zircon-like structured and crystallizes in the tetragonal I4_1/acd space group. The structure is three-dimensional. there are two inequivalent Ho3+ sites. In the first Ho3+ site, Ho3+ is bonded in a 8-coordinate geometry to eight S2- atoms. There are four shorter (2.82 Å) and four longer (2.99 Å) Ho–S bond lengths. In the second Ho3+ site, Ho3+ is bonded in a distorted body-centered cubic geometry to eight S2- atoms. All Ho–S bond lengths are 2.90 Å. P5+ is bonded in a tetrahedral geometry to four S2- atoms. There are two shorter (2.04 Å) and two longer (2.05 Å) P–S bond lengths. There are two inequivalent S2- sites. In the first S2- site, S2- is bonded in a 3-coordinate geometry to two Ho3+ and one P5+ atom. In the second S2- site, S2- is bonded in a distorted T-shaped geometry to two Ho3+ and one P5+ atom.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on SrMoO4 by Materials Project

SrMoO4 is Zircon-like structured and crystallizes in the tetragonal I4_1/a space group. The structure is three-dimensional. Sr2+ is bonded in a 8-coordinate geometry to eight equivalent O2- atoms. There are four shorter (2.62 Å) and four longer (2.65 Å) Sr–O bond lengths. Mo6+ is bonded in a tetrahedral geometry to four equivalent O2- atoms. All Mo–O bond lengths are 1.80 Å. O2- is bonded in a 1-coordinate geometry to two equivalent Sr2+ and one Mo6+ atom.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on ErVO4 by Materials Project

ErVO4 is Zircon-like structured and crystallizes in the tetragonal I4_1/a space group. The structure is three-dimensional. Er3+ is bonded in a 8-coordinate geometry to eight equivalent O2- atoms. There are four shorter (2.34 Å) and four longer (2.38 Å) Er–O bond lengths. V5+ is bonded in a tetrahedral geometry to four equivalent O2- atoms. All V–O bond lengths are 1.76 Å. O2- is bonded in a 3-coordinate geometry to two equivalent Er3+ and one V5+ atom.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on CdMoO4 by Materials Project

CdMoO4 is Zircon-like structured and crystallizes in the tetragonal I4_1/a space group. The structure is three-dimensional. Mo6+ is bonded in a tetrahedral geometry to four equivalent O2- atoms. All Mo–O bond lengths are 1.81 Å. Cd2+ is bonded in a 8-coordinate geometry to eight equivalent O2- atoms. There are four shorter (2.44 Å) and four longer (2.46 Å) Cd–O bond lengths. O2- is bonded in a 3-coordinate geometry to one Mo6+ and two equivalent Cd2+ atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on BaWO4 by Materials Project

BaWO4 is Zircon-like structured and crystallizes in the tetragonal I4_1/a space group. The structure is three-dimensional. Ba2+ is bonded in a 8-coordinate geometry to eight equivalent O2- atoms. There are four shorter (2.79 Å) and four longer (2.83 Å) Ba–O bond lengths. W6+ is bonded in a tetrahedral geometry to four equivalent O2- atoms. All W–O bond lengths are 1.82 Å. O2- is bonded in a 1-coordinate geometry to two equivalent Ba2+ and one W6+ atom.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on HoCrO4 by Materials Project

HoCrO4 is Zircon-like structured and crystallizes in the tetragonal I4_1/a space group. The structure is three-dimensional. Ho3+ is bonded in a 8-coordinate geometry to eight equivalent O2- atoms. There are four shorter (2.33 Å) and four longer (2.41 Å) Ho–O bond lengths. Cr5+ is bonded in a tetrahedral geometry to four equivalent O2- atoms. All Cr–O bond lengths are 1.74 Å. O2- is bonded in a 3-coordinate geometry to two equivalent Ho3+ and one Cr5+ atom.

36 MATERIALS SCIENCE↗