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

Materials Data on SrWO4 by Materials Project

SrWO4 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 (2.61 Å) and four longer (2.65 Å) Sr–O bond lengths. W6+ is bonded in a tetrahedral geometry to four equivalent O2- atoms. All W–O bond lengths are 1.83 Å. O2- is bonded in a 3-coordinate geometry to two equivalent Sr2+ and one W6+ atom.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on LuVO4 by Materials Project

LuVO4 is Zircon-like structured and crystallizes in the tetragonal I4_1/a space group. The structure is three-dimensional. Lu3+ is bonded in a 8-coordinate geometry to eight equivalent O2- atoms. There are four shorter (2.30 Å) and four longer (2.35 Å) Lu–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 distorted trigonal planar geometry to two equivalent Lu3+ and one V5+ atom.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on CaMoO4 by Materials Project

CaMoO4 is Zircon-like structured and crystallizes in the tetragonal I4_1/a space group. The structure is three-dimensional. Ca2+ is bonded in a 8-coordinate geometry to eight equivalent O2- atoms. There are four shorter (2.48 Å) and four longer (2.51 Å) Ca–O bond lengths. Mo6+ is bonded in a tetrahedral geometry to four equivalent O2- atoms. All Mo–O bond lengths are 1.81 Å. O2- is bonded in a 3-coordinate geometry to two equivalent Ca2+ and one Mo6+ atom.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on CaWO4 by Materials Project

CaWO4 is Zircon-like structured and crystallizes in the tetragonal I4_1/a space group. The structure is three-dimensional. Ca2+ is bonded in a 8-coordinate geometry to eight equivalent O2- atoms. There are four shorter (2.47 Å) and four longer (2.51 Å) Ca–O bond lengths. W6+ is bonded in a tetrahedral geometry to four equivalent O2- atoms. All W–O bond lengths are 1.83 Å. O2- is bonded in a distorted trigonal planar geometry to two equivalent Ca2+ and one W6+ atom.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on EuPSe3 by Materials Project

EuPSe3 is Zircon-like structured and crystallizes in the monoclinic P2_1/c space group. The structure is three-dimensional. Eu2+ is bonded in a 8-coordinate geometry to eight Se2- atoms. There are a spread of Eu–Se bond distances ranging from 3.14–3.36 Å. P4+ is bonded in a trigonal non-coplanar geometry to three Se2- atoms. There are one shorter (2.21 Å) and two longer (2.22 Å) P–Se bond lengths. There are three inequivalent Se2- sites. In the first Se2- site, Se2- is bonded in a 3-coordinate geometry to two equivalent Eu2+ and one P4+ atom. In the second Se2- site, Se2- is bonded in a 1-coordinate geometry to three equivalent Eu2+ and one P4+ atom. In the third Se2- site, Se2- is bonded in a 4-coordinate geometry to three equivalent Eu2+ and one P4+ atom.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on SrZnCl4 by Materials Project

SrZnCl4 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 Cl1- atoms. There are four shorter (3.00 Å) and four longer (3.11 Å) Sr–Cl bond lengths. Zn2+ is bonded in a tetrahedral geometry to four equivalent Cl1- atoms. All Zn–Cl bond lengths are 2.31 Å. Cl1- is bonded in a distorted trigonal planar geometry to two equivalent Sr2+ and one Zn2+ atom.

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