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All sourcesNASA NTRSDOE OSTI
DOE OSTI2020

Materials Data on YF3 by Materials Project

YF3 is Cementite structured and crystallizes in the orthorhombic Pnma space group. The structure is three-dimensional. Y3+ is bonded in a 9-coordinate geometry to eight F1- atoms. There are a spread of Y–F bond distances ranging from 2.25–2.35 Å. There are two inequivalent F1- sites. In the first F1- site, F1- is bonded in a 2-coordinate geometry to two equivalent Y3+ atoms. In the second F1- site, F1- is bonded in a distorted trigonal planar geometry to three equivalent Y3+ atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on YF3 by Materials Project

YF3 crystallizes in the cubic Pm-3m space group. The structure is three-dimensional. Y3+ is bonded in a distorted body-centered cubic geometry to ten F1- atoms. There are eight shorter (2.36 Å) and two longer (2.69 Å) Y–F bond lengths. There are two inequivalent F1- sites. In the first F1- site, F1- is bonded in a trigonal non-coplanar geometry to three equivalent Y3+ and one F1- atom. The F–F bond length is 2.40 Å. In the second F1- site, F1- is bonded in a 6-coordinate geometry to six equivalent Y3+ and eight equivalent F1- atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on YF3 by Materials Project

YF3 crystallizes in the trigonal P-3c1 space group. The structure is three-dimensional. Y3+ is bonded in a 9-coordinate geometry to nine F1- atoms. There are a spread of Y–F bond distances ranging from 2.29–2.50 Å. There are three inequivalent F1- sites. In the first F1- site, F1- is bonded in a distorted trigonal planar geometry to three equivalent Y3+ atoms. In the second F1- site, F1- is bonded in a 3-coordinate geometry to three equivalent Y3+ atoms. In the third F1- site, F1- is bonded in a trigonal planar geometry to three equivalent Y3+ atoms.

36 MATERIALS SCIENCE↗
NASA NTRS1990

Wet chemical passivation of YBa2Cu3O(7-x)

Wet chemical techniques are described for treatment of YBa2Cu3O(7-x) surfaces, which result in the formation of native compounds known to have little or no reactivity to water. Suitable native compounds include CuI, BaSO4, CuS, Cu2S, YF3, and the oxalates. Formation of surface layers in which these nonreactive native compounds are major constituents is verified with X-ray photoelectron spectroscopy (XPS) measurements on YBa2Cu3O(7-x) films treated with dilute solutions of HI, H2SO4, Na2S, HF, or H2C2O4. No significant changes are observed in the XPS spectra when the sulfide, sulfate, or oxalate films are dipped in water, while the iodide and fluoride films show evidence of reaction with water. X-ray diffraction measurements show that the superconducting phase is absent in the sulfide film, but is unaffected by the oxalate and sulfate treatments.

Vasquez, R. P.↗
NASA NTRS1991

Long-Lifetime Laser Materials For Effective Diode Pumping

Long quantum lifetimes reduce number of diodes required to pump. Pumping by laser diodes demonstrated with such common Nd laser materials as neodymium:yttrium aluminum garnet (Nd:YAG) and Nd:YLiF4, but such materials as Nd:LaF3, Nd:NaF.9YF3, and possibly Nd:YF3 more useful because of long lifetimes of their upper laser energy levels. Cost effectiveness primary advantage of solid-state laser materials having longer upper-laser-level lifetimes. Because cost of diodes outweighs cost of laser material by perhaps two orders of magnitude, cost reduced significantly.

Barnes, Norman P.↗