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DOE OSTI2020

Materials Data on La(TmS2)3 by Materials Project

La(TmS2)3 crystallizes in the monoclinic P2_1/m space group. The structure is three-dimensional. there are three inequivalent Tm3+ sites. In the first Tm3+ site, Tm3+ is bonded to seven S2- atoms to form distorted TmS7 pentagonal bipyramids that share corners with three TmS6 octahedra, edges with two equivalent TmS6 octahedra, and edges with four equivalent TmS7 pentagonal bipyramids. The corner-sharing octahedra tilt angles range from 39–51°. There are a spread of Tm–S bond distances ranging from 2.67–2.90 Å. In the second Tm3+ site, Tm3+ is bonded to six S2- atoms to form TmS6 octahedra that share corners with three equivalent TmS6 octahedra, a cornercorner with one TmS7 pentagonal bipyramid, edges with four equivalent TmS6 octahedra, and edges with two equivalent TmS7 pentagonal bipyramids. The corner-sharing octahedra tilt angles range from 53–62°. There are a spread of Tm–S bond distances ranging from 2.65–2.76 Å. In the third Tm3+ site, Tm3+ is bonded to six S2- atoms to form TmS6 octahedra that share corners with three equivalent TmS6 octahedra, corners with two equivalent TmS7 pentagonal bipyramids, and edges with four equivalent TmS6 octahedra. The corner-sharing octahedra tilt angles range from 53–62°. There are a spread of Tm–S bond distances ranging from 2.63–2.77 Å. La3+ is bonded in a 8-coordinate geometry to eight S2- atoms. There are a spread of La–S bond distances ranging from 2.93–3.06 Å. There are six inequivalent S2- sites. In the first S2- site, S2- is bonded in a 4-coordinate geometry to four Tm3+ atoms. In the second S2- site, S2- is bonded to three Tm3+ and one La3+ atom to form distorted SLaTm3 trigonal pyramids that share corners with two equivalent SLa2Tm3 square pyramids, corners with four SLa2Tm3 trigonal bipyramids, corners with two equivalent SLaTm3 trigonal pyramids, edges with three equivalent SLa2Tm3 square pyramids, and edges with two equivalent SLa3Tm2 trigonal bipyramids. In the third S2- site, S2- is bonded in a rectangular see-saw-like geometry to four Tm3+ atoms. In the fourth S2- site, S2- is bonded to three equivalent Tm3+ and two equivalent La3+ atoms to form distorted SLa2Tm3 square pyramids that share corners with six SLa2Tm3 trigonal bipyramids, corners with two equivalent SLaTm3 trigonal pyramids, edges with four equivalent SLa2Tm3 square pyramids, edges with two SLa2Tm3 trigonal bipyramids, and edges with three equivalent SLaTm3 trigonal pyramids. In the fifth S2- site, S2- is bonded to three Tm3+ and two equivalent La3+ atoms to form distorted SLa2Tm3 trigonal bipyramids that share corners with two equivalent SLa2Tm3 square pyramids, corners with two equivalent SLa3Tm2 trigonal bipyramids, corners with three equivalent SLaTm3 trigonal pyramids, an edgeedge with one SLa2Tm3 square pyramid, and edges with five SLa2Tm3 trigonal bipyramids. In the sixth S2- site, S2- is bonded to two equivalent Tm3+ and three equivalent La3+ atoms to form distorted SLa3Tm2 trigonal bipyramids that share corners with four equivalent SLa2Tm3 square pyramids, corners with two equivalent SLa2Tm3 trigonal bipyramids, a cornercorner with one SLaTm3 trigonal pyramid, an edgeedge with one SLa2Tm3 square pyramid, edges with seven SLa2Tm3 trigonal bipyramids, and edges with two equivalent SLaTm3 trigonal pyramids.

36 MATERIALS SCIENCE↗

DOE OSTI2020

Materials Data on La(ZnP)3 by Materials Project

La(ZnP)3 crystallizes in the hexagonal P6_3/mmc space group. The structure is three-dimensional. La3+ is bonded to six equivalent P3- atoms to form LaP6 octahedra that share corners with six equivalent ZnP4 tetrahedra, edges with six equivalent LaP6 octahedra, and edges with six equivalent ZnP4 tetrahedra. All La–P bond lengths are 2.95 Å. There are two inequivalent Zn2+ sites. In the first Zn2+ site, Zn2+ is bonded in a trigonal planar geometry to three equivalent P3- atoms. All Zn–P bond lengths are 2.36 Å. In the second Zn2+ site, Zn2+ is bonded to four P3- atoms to form ZnP4 tetrahedra that share corners with three equivalent LaP6 octahedra, corners with seven equivalent ZnP4 tetrahedra, and edges with three equivalent LaP6 octahedra. The corner-sharing octahedral tilt angles are 17°. There are one shorter (2.43 Å) and three longer (2.50 Å) Zn–P bond lengths. There are two inequivalent P3- sites. In the first P3- site, P3- is bonded to three equivalent La3+ and three equivalent Zn2+ atoms to form distorted PLa3Zn3 octahedra that share corners with three equivalent PLa3Zn3 octahedra, corners with three equivalent PZn5 trigonal bipyramids, and edges with nine equivalent PLa3Zn3 octahedra. The corner-sharing octahedral tilt angles are 0°. In the second P3- site, P3- is bonded to five Zn2+ atoms to form PZn5 trigonal bipyramids that share corners with six equivalent PLa3Zn3 octahedra and corners with six equivalent PZn5 trigonal bipyramids. The corner-sharing octahedral tilt angles are 70°.

36 MATERIALS SCIENCE↗

DOE OSTI2020

Materials Data on La(YC3)2 by Materials Project

La(YC3)2 crystallizes in the monoclinic C2/m space group. The structure is three-dimensional. La3+ is bonded in a 10-coordinate geometry to ten C+1.50- atoms. There are a spread of La–C bond distances ranging from 2.62–2.87 Å. Y3+ is bonded in a 10-coordinate geometry to ten C+1.50- atoms. There are a spread of Y–C bond distances ranging from 2.43–2.76 Å. There are three inequivalent C+1.50- sites. In the first C+1.50- site, C+1.50- is bonded in a 6-coordinate geometry to three equivalent La3+, two equivalent Y3+, and one C+1.50- atom. The C–C bond length is 1.30 Å. In the second C+1.50- site, C+1.50- is bonded in a 2-coordinate geometry to five equivalent Y3+ and one C+1.50- atom. The C–C bond length is 1.30 Å. In the third C+1.50- site, C+1.50- is bonded in a 2-coordinate geometry to two equivalent La3+, three equivalent Y3+, and one C+1.50- atom.

36 MATERIALS SCIENCE↗

DOE OSTI2020

Materials Data on La(SmB8)3 by Materials Project

La(SmB8)3 is Calcium hexaboride-derived structured and crystallizes in the orthorhombic Cmmm space group. The structure is three-dimensional. there are two inequivalent Sm3+ sites. In the first Sm3+ site, Sm3+ is bonded in a 12-coordinate geometry to twenty-four B+0.50- atoms. There are a spread of Sm–B bond distances ranging from 3.01–3.07 Å. In the second Sm3+ site, Sm3+ is bonded in a 12-coordinate geometry to twenty-four B+0.50- atoms. There are twelve shorter (3.01 Å) and twelve longer (3.05 Å) Sm–B bond lengths. La3+ is bonded in a 12-coordinate geometry to twenty-four B+0.50- atoms. There are a spread of La–B bond distances ranging from 3.01–3.05 Å. There are five inequivalent B+0.50- sites. In the first B+0.50- site, B+0.50- is bonded in a 1-coordinate geometry to three Sm3+, one La3+, and five B+0.50- atoms. There is one shorter (1.65 Å) and four longer (1.75 Å) B–B bond length. In the second B+0.50- site, B+0.50- is bonded in a 1-coordinate geometry to three Sm3+, one La3+, and five B+0.50- atoms. All B–B bond lengths are 1.75 Å. In the third B+0.50- site, B+0.50- is bonded in a 1-coordinate geometry to four Sm3+ and five B+0.50- atoms. The B–B bond length is 1.64 Å. In the fourth B+0.50- site, B+0.50- is bonded in a 1-coordinate geometry to three Sm3+, one La3+, and five B+0.50- atoms. The B–B bond length is 1.65 Å. In the fifth B+0.50- site, B+0.50- is bonded in a 1-coordinate geometry to two equivalent Sm3+, two equivalent La3+, and five B+0.50- atoms. The B–B bond length is 1.66 Å.

36 MATERIALS SCIENCE↗

DOE OSTI2020

Materials Data on La(YbS2)3 by Materials Project

La(YbS2)3 crystallizes in the monoclinic P2_1/m space group. The structure is three-dimensional. there are three inequivalent Yb3+ sites. In the first Yb3+ site, Yb3+ is bonded to six S2- atoms to form distorted YbS6 pentagonal pyramids that share corners with three equivalent YbS6 octahedra, corners with two equivalent YbS5 square pyramids, and edges with four equivalent YbS6 pentagonal pyramids. The corner-sharing octahedra tilt angles range from 65–75°. There are a spread of Yb–S bond distances ranging from 2.69–2.93 Å. In the second Yb3+ site, Yb3+ is bonded to six S2- atoms to form YbS6 octahedra that share corners with three equivalent YbS6 pentagonal pyramids, corners with three equivalent YbS5 square pyramids, and edges with four equivalent YbS6 octahedra. There are a spread of Yb–S bond distances ranging from 2.67–3.13 Å. In the third Yb3+ site, Yb3+ is bonded to five S2- atoms to form distorted YbS5 square pyramids that share corners with three equivalent YbS6 octahedra, corners with two equivalent YbS6 pentagonal pyramids, and edges with two equivalent YbS5 square pyramids. The corner-sharing octahedra tilt angles range from 56–71°. There are a spread of Yb–S bond distances ranging from 2.60–2.96 Å. La3+ is bonded in a 8-coordinate geometry to eight S2- atoms. There are a spread of La–S bond distances ranging from 2.85–3.05 Å. There are six inequivalent S2- sites. In the first S2- site, S2- is bonded to four Yb3+ atoms to form distorted SYb4 tetrahedra that share corners with five SYb4 tetrahedra, corners with four equivalent SLa3Yb2 trigonal bipyramids, corners with three equivalent SYb4 trigonal pyramids, edges with two equivalent SYb4 tetrahedra, and an edgeedge with one SLa3Yb2 trigonal bipyramid. In the second S2- site, S2- is bonded to three Yb3+ and one La3+ atom to form distorted SLaYb3 tetrahedra that share corners with five SYb4 tetrahedra, a cornercorner with one SLa3Yb2 trigonal bipyramid, corners with two equivalent SYb4 trigonal pyramids, and edges with two equivalent SLa3Yb2 trigonal bipyramids. In the third S2- site, S2- is bonded to four Yb3+ atoms to form a mixture of edge and corner-sharing SYb4 trigonal pyramids. In the fourth S2- site, S2- is bonded in a 5-coordinate geometry to two equivalent Yb3+, two equivalent La3+, and one S2- atom. The S–S bond length is 2.11 Å. In the fifth S2- site, S2- is bonded in a 5-coordinate geometry to two equivalent Yb3+, two equivalent La3+, and one S2- atom. In the sixth S2- site, S2- is bonded to two equivalent Yb3+ and three equivalent La3+ atoms to form distorted SLa3Yb2 trigonal bipyramids that share corners with five SYb4 tetrahedra, edges with three SYb4 tetrahedra, and edges with four equivalent SLa3Yb2 trigonal bipyramids.

36 MATERIALS SCIENCE↗

DOE OSTI2020

Materials Data on La(Ho2C5)2 by Materials Project

La(Ho2C5)2 crystallizes in the monoclinic C2/m space group. The structure is three-dimensional. there are two inequivalent Ho3+ sites. In the first Ho3+ site, Ho3+ is bonded in a 10-coordinate geometry to ten C+1.50- atoms. There are a spread of Ho–C bond distances ranging from 2.46–2.75 Å. In the second Ho3+ site, Ho3+ is bonded in a 10-coordinate geometry to ten C+1.50- atoms. There are a spread of Ho–C bond distances ranging from 2.40–2.72 Å. La3+ is bonded in a distorted q4 geometry to ten C+1.50- atoms. There are a spread of La–C bond distances ranging from 2.59–2.83 Å. There are five inequivalent C+1.50- sites. In the first C+1.50- site, C+1.50- is bonded to three Ho3+, two equivalent La3+, and one C+1.50- atom to form a mixture of distorted corner and edge-sharing CLa2Ho3C octahedra. The corner-sharing octahedra tilt angles range from 0–81°. The C–C bond length is 1.30 Å. In the second C+1.50- site, C+1.50- is bonded in a 6-coordinate geometry to five Ho3+ and one C+1.50- atom. The C–C bond length is 1.30 Å. In the third C+1.50- site, C+1.50- is bonded in a 6-coordinate geometry to five Ho3+ and one C+1.50- atom. In the fourth C+1.50- site, C+1.50- is bonded in a 2-coordinate geometry to four Ho3+, one La3+, and one C+1.50- atom. In the fifth C+1.50- site, C+1.50- is bonded in a 6-coordinate geometry to three equivalent Ho3+, two equivalent La3+, and one C+1.50- atom. The C–C bond length is 1.31 Å.

36 MATERIALS SCIENCE↗

DOE OSTI2020

Materials Data on La(HoS2)3 by Materials Project

La(HoS2)3 crystallizes in the monoclinic P2_1/m space group. The structure is three-dimensional. there are three inequivalent Ho3+ sites. In the first Ho3+ site, Ho3+ is bonded to seven S2- atoms to form distorted HoS7 pentagonal bipyramids that share corners with three HoS6 octahedra, edges with two equivalent HoS6 octahedra, and edges with four equivalent HoS7 pentagonal bipyramids. The corner-sharing octahedra tilt angles range from 39–51°. There are a spread of Ho–S bond distances ranging from 2.70–2.93 Å. In the second Ho3+ site, Ho3+ is bonded to six S2- atoms to form HoS6 octahedra that share corners with three equivalent HoS6 octahedra, a cornercorner with one HoS7 pentagonal bipyramid, edges with four equivalent HoS6 octahedra, and edges with two equivalent HoS7 pentagonal bipyramids. The corner-sharing octahedra tilt angles range from 53–62°. There are a spread of Ho–S bond distances ranging from 2.68–2.78 Å. In the third Ho3+ site, Ho3+ is bonded to six S2- atoms to form HoS6 octahedra that share corners with three equivalent HoS6 octahedra, corners with two equivalent HoS7 pentagonal bipyramids, and edges with four equivalent HoS6 octahedra. The corner-sharing octahedra tilt angles range from 53–62°. There are a spread of Ho–S bond distances ranging from 2.66–2.80 Å. La3+ is bonded in a 8-coordinate geometry to eight S2- atoms. There are a spread of La–S bond distances ranging from 2.94–3.08 Å. There are six inequivalent S2- sites. In the first S2- site, S2- is bonded in a 4-coordinate geometry to four Ho3+ atoms. In the second S2- site, S2- is bonded to three Ho3+ and one La3+ atom to form distorted SLaHo3 trigonal pyramids that share corners with two equivalent SLa2Ho3 square pyramids, corners with four SLa2Ho3 trigonal bipyramids, corners with two equivalent SLaHo3 trigonal pyramids, edges with three equivalent SLa2Ho3 square pyramids, and edges with two equivalent SLa3Ho2 trigonal bipyramids. In the third S2- site, S2- is bonded in a rectangular see-saw-like geometry to four Ho3+ atoms. In the fourth S2- site, S2- is bonded to three equivalent Ho3+ and two equivalent La3+ atoms to form distorted SLa2Ho3 square pyramids that share corners with six SLa2Ho3 trigonal bipyramids, corners with two equivalent SLaHo3 trigonal pyramids, edges with four equivalent SLa2Ho3 square pyramids, edges with two SLa2Ho3 trigonal bipyramids, and edges with three equivalent SLaHo3 trigonal pyramids. In the fifth S2- site, S2- is bonded to three Ho3+ and two equivalent La3+ atoms to form distorted SLa2Ho3 trigonal bipyramids that share corners with two equivalent SLa2Ho3 square pyramids, corners with two equivalent SLa3Ho2 trigonal bipyramids, corners with three equivalent SLaHo3 trigonal pyramids, an edgeedge with one SLa2Ho3 square pyramid, and edges with five SLa2Ho3 trigonal bipyramids. In the sixth S2- site, S2- is bonded to two equivalent Ho3+ and three equivalent La3+ atoms to form distorted SLa3Ho2 trigonal bipyramids that share corners with four equivalent SLa2Ho3 square pyramids, corners with two equivalent SLa2Ho3 trigonal bipyramids, a cornercorner with one SLaHo3 trigonal pyramid, an edgeedge with one SLa2Ho3 square pyramid, edges with seven SLa2Ho3 trigonal bipyramids, and edges with two equivalent SLaHo3 trigonal pyramids.

36 MATERIALS SCIENCE↗

DOE OSTI2020

Materials Data on La(CoB)4 by Materials Project

La(CoB)4 crystallizes in the tetragonal P4_2/n space group. The structure is three-dimensional. La3+ is bonded in a 12-coordinate geometry to twelve equivalent B3- atoms. There are a spread of La–B bond distances ranging from 2.82–3.31 Å. Co+2.25+ is bonded in a 5-coordinate geometry to five equivalent B3- atoms. There are a spread of Co–B bond distances ranging from 2.00–2.52 Å. B3- is bonded in a 5-coordinate geometry to three equivalent La3+, five equivalent Co+2.25+, and one B3- atom. The B–B bond length is 1.81 Å.

36 MATERIALS SCIENCE↗

DOE OSTI2020

Materials Data on La(YS2)3 by Materials Project

La(YS2)3 crystallizes in the monoclinic P2_1/m space group. The structure is three-dimensional. La3+ is bonded in a 8-coordinate geometry to eight S2- atoms. There are a spread of La–S bond distances ranging from 2.95–3.07 Å. There are three inequivalent Y3+ sites. In the first Y3+ site, Y3+ is bonded to six S2- atoms to form YS6 octahedra that share corners with three equivalent YS6 octahedra, a cornercorner with one YS7 pentagonal bipyramid, edges with four equivalent YS6 octahedra, and edges with two equivalent YS7 pentagonal bipyramids. The corner-sharing octahedra tilt angles range from 53–63°. There are a spread of Y–S bond distances ranging from 2.68–2.79 Å. In the second Y3+ site, Y3+ is bonded to seven S2- atoms to form distorted YS7 pentagonal bipyramids that share corners with three YS6 octahedra, edges with two equivalent YS6 octahedra, and edges with four equivalent YS7 pentagonal bipyramids. The corner-sharing octahedra tilt angles range from 39–51°. There are a spread of Y–S bond distances ranging from 2.72–2.94 Å. In the third Y3+ site, Y3+ is bonded to six S2- atoms to form YS6 octahedra that share corners with three equivalent YS6 octahedra, corners with two equivalent YS7 pentagonal bipyramids, and edges with four equivalent YS6 octahedra. The corner-sharing octahedra tilt angles range from 53–63°. There are a spread of Y–S bond distances ranging from 2.67–2.81 Å. There are six inequivalent S2- sites. In the first S2- site, S2- is bonded in a 4-coordinate geometry to four Y3+ atoms. In the second S2- site, S2- is bonded to two equivalent La3+ and three equivalent Y3+ atoms to form distorted SLa2Y3 square pyramids that share corners with six SLa3Y2 trigonal bipyramids, corners with two equivalent SLaY3 trigonal pyramids, edges with four equivalent SLa2Y3 square pyramids, edges with two SLa3Y2 trigonal bipyramids, and edges with three equivalent SLaY3 trigonal pyramids. In the third S2- site, S2- is bonded in a distorted rectangular see-saw-like geometry to four Y3+ atoms. In the fourth S2- site, S2- is bonded to two equivalent La3+ and three Y3+ atoms to form distorted SLa2Y3 trigonal bipyramids that share corners with two equivalent SLa2Y3 square pyramids, corners with two equivalent SLa3Y2 trigonal bipyramids, corners with three equivalent SLaY3 trigonal pyramids, an edgeedge with one SLa2Y3 square pyramid, and edges with five SLa2Y3 trigonal bipyramids. In the fifth S2- site, S2- is bonded to three equivalent La3+ and two equivalent Y3+ atoms to form distorted SLa3Y2 trigonal bipyramids that share corners with four equivalent SLa2Y3 square pyramids, corners with two equivalent SLa2Y3 trigonal bipyramids, a cornercorner with one SLaY3 trigonal pyramid, an edgeedge with one SLa2Y3 square pyramid, edges with seven SLa2Y3 trigonal bipyramids, and edges with two equivalent SLaY3 trigonal pyramids. In the sixth S2- site, S2- is bonded to one La3+ and three Y3+ atoms to form distorted SLaY3 trigonal pyramids that share corners with two equivalent SLa2Y3 square pyramids, corners with four SLa2Y3 trigonal bipyramids, corners with two equivalent SLaY3 trigonal pyramids, edges with three equivalent SLa2Y3 square pyramids, and edges with two equivalent SLa3Y2 trigonal bipyramids.

36 MATERIALS SCIENCE↗

DOE OSTI2020

Materials Data on La(ErSe2)2 by Materials Project

La(ErSe2)2 crystallizes in the tetragonal I-42d space group. The structure is three-dimensional. Er3+ is bonded to eight equivalent Se2- atoms to form distorted ErSe8 hexagonal bipyramids that share corners with four equivalent ErSe8 hexagonal bipyramids, corners with four equivalent LaSe8 hexagonal bipyramids, edges with four equivalent ErSe8 hexagonal bipyramids, faces with four equivalent ErSe8 hexagonal bipyramids, and faces with four equivalent LaSe8 hexagonal bipyramids. There are a spread of Er–Se bond distances ranging from 2.87–3.22 Å. La2+ is bonded to eight equivalent Se2- atoms to form distorted LaSe8 hexagonal bipyramids that share corners with eight equivalent ErSe8 hexagonal bipyramids, edges with four equivalent LaSe8 hexagonal bipyramids, and faces with eight equivalent ErSe8 hexagonal bipyramids. There are four shorter (3.00 Å) and four longer (3.17 Å) La–Se bond lengths. Se2- is bonded in a 6-coordinate geometry to four equivalent Er3+ and two equivalent La2+ atoms.

36 MATERIALS SCIENCE↗

DOE OSTI2020

Calcium fluoride as a dominating matrix for quantitative analysis by laser ablation-inductively coupled plasma-mass spectrometry (LA-ICP-MS): A feasibility study

Here, calcium fluoride formed by the reaction between ammonium bifluoride and calcium chloride was investigated as a dominating matrix for quantitative analysis by laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS). Transformation from a solid sample to the calcium fluoride-based matrix permitted quantitative analysis based on calibration standards made from elemental standards. A low abundance stable calcium isotope, i.e. 44 Ca + , was monitored as the internal standard for quantitative analysis by LA-ICP-MS. Correlation coefficient factors for multiple elements were obtained with values over 0.999. The results for multiple elements in a certified reference material of soil (NIST SRM 2710a) agreed with the certified values in the range of expanded uncertainty, indicating the present method was valid for quantitation of elements in solid samples.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗

DOE OSTI2020

Mixed Ionic–Electronic Conductor of Perovskite Li x La y MO 3-δ toward Carbon-Free Cathode for Reversible Lithium–Air Batteries

Mixed ionic–electronic conductors (MIECs) can play a pivotal role in achieving high energies and power densities in rechargeable batteries owing to their ability to simultaneously conduct ions and electrons. In our study, a new strategy is proposed wherein late 3d transition metals (TMs) are substituted into a perovskite Li-ion conductor to transform it into a Li-containing MIEC. First-principles calculations show that perovskite Li x La y MO 3 with late 3d TMs have a low oxygen vacancy formation energy, implying high electron carrier concentrations corresponding to high electronic conductivity. The activation barriers for Li diffusion in Li x La y MO 3 (M = Ti, Cr, Mn, Fe, and Co) are below 0.411 eV, resulting in high Li-ion conductivity. The designed perovskites of Li0.34La 0.55 MnO 3-δ experimentally prove to have high electronic (2.04 × 10 -3 S cm -1 ) and Li-ion (8.53 × 10 -5 S cm -1 ) conductivities, and when applied in a carbon-free cathode of a Li–air cell, they deliver superior reversibility at 0.21 mAh cm -2 over 100 charge/discharge cycles while avoiding the degradation associated with carbonaceous materials. Finally, this strategy enables the effective design of Li-conducting MIEC and reversible Li–air batteries.

36 MATERIALS SCIENCE↗

DOE OSTI2023

Stabilization Of The CN 3 5− Anion In Recoverable High‐pressure Ln 3 O 2 (CN 3 ) (Ln=La, Eu, Gd, Tb, Ho, Yb) Oxoguanidinates

Abstract A series of isostructural Ln 3 O 2 (CN 3 ) (Ln=La, Eu, Gd, Tb, Ho, Yb) oxoguanidinates was synthesized under high‐pressure (25–54 GPa) high‐temperature (2000–3000 K) conditions in laser‐heated diamond anvil cells. The crystal structure of this novel class of compounds was determined via synchrotron single‐crystal X‐ray diffraction (SCXRD) as well as corroborated by X‐ray absorption near edge structure (XANES) measurements and density functional theory (DFT) calculations. The Ln 3 O 2 (CN 3 ) solids are composed of the hitherto unknown CN 3 5− guanidinate anion—deprotonated guanidine. Changes in unit cell volumes and compressibility of Ln 3 O 2 (CN 3 ) (Ln=La, Eu, Gd, Tb, Ho, Yb) compounds are found to be dictated by the lanthanide contraction phenomenon. Decompression experiments show that Ln 3 O 2 (CN 3 ) compounds are recoverable to ambient conditions. The stabilization of the CN 3 5− guanidinate anion at ambient conditions provides new opportunities in inorganic and organic synthetic chemistry.

Chemistry↗

DOE OSTI2021

Gallium‐Doping Effects on Structure, Lithium‐Conduction, and Thermochemical Stability of Li 7‐3 x Ga x La 3 Zr 2 O 12 Garnet‐Type Electrolytes

Abstract One of the most promising electrolytes for all‐solid‐state lithium batteries is Li 7 La 3 Zr 2 O 12 . Previously, their thermodynamic stability, Li‐ion conductivity, and structural features induced by Ga‐doping have not been empirically determined or correlated. Here, their interplay was examined for Li 7−3 x Ga x La 3 Zr 2 O 12 with target x Ga=0, 0.25, 0.50, 0.75, and 1.00 atoms per formula unit (apfu). Formation enthalpies, obtained with calorimetry and found to be exothermic at all compositions, linearly decreased in stability with increased x Ga. At dilute x Ga substitution, the formation enthalpy curve shifted stepwise endothermically, and the conductivity increased to a maximum, coinciding with 0.529 Ga apfu. This correlated with percolation threshold analysis (0.558 Ga apfu). Further substitution (0.787 Ga apfu) produced a large decrease in the stability and conductivity due to a large increase in point defects and blocked Li‐migration pathways. At x Ga=1.140 apfu, a small exothermic shift was related to defect cluster organization extending the Li hopping distance and decreased Li‐ion conductivity.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗

DOE OSTI2021

Thermal Processing Conditions for the Synthesis of Near Theoretical Density Li 5 La 3 Ta 2 O 12 Ceramics for Ceramic Dual-Mode Detectors

A family of Li-containing garnet compounds, extensively investigated for Li-ion solid electrolyte applications, show great potential to be developed into transparent ceramic dual-mode scintillators. In particular, Li 5 La 3 Ta 2 O 12 (LLTaO) shows promise as an efficient dual-mode scintillator due to its high Li content, high density, non-hygroscopicity, and high effective-Z. Often the synthesis of LLTaO ceramics involves solid state processing techniques starting with oxide and carbonate powders, calcining, sintering for the removal of residual porosity, and post-processing. This study focuses on two objectives: (1) establishing thermal processing boundary conditions for a flexible alkoxide-based sol-gel method for synthesizing fine-grained powders; and (2), consolidating powders via hot-pressing to form high-density ceramics. In this study, near single-phase ceramics were achieved by hot-pressing sol-gel powders with varying amounts of excess Li. Rietveld refinements were used to analyze X-ray diffraction data and provide a quantitative evaluation of the phases present in the hot pressed ceramics. Some of the diffraction data showed large low angle peak asymmetry, suggesting the presence of two cubic Li 5 La 3 Ta 2 O 12 garnet phases with different lattice parameters. Depending on the synthesis and processing conditions, the refinement revealed ~ 90 wt% concentration of a phase with a ≈ 12.8 Å and ~ 10 wt% concentration of a phase with a ≈ 12.9 Å, indicating a remaining excess of Li in the hot pressed ceramics in the large lattice parameter phase. These synthesis experiments allowed for the determination of a baseline for Li loss during hot-pressing. X-ray excited radioluminescence and photoluminescence excitation and emission spectra were obtained from the hot pressed ceramics. In conclusion, the measured emission spectra featured broad tantalate emission and line emissions likely from a rare-earth impurity.

36 MATERIALS SCIENCE↗

DOE OSTI2021

La 3+ and Y 3+ interactions with the carboxylic acid moiety at the liquid/vapor interface: Identification of binding complexes, charge reversal, and detection limits

Specific interactions of yttrium and lanthanum ions with a fatty acid Langmuir monolayer were investigated using vibrational sum frequency spectroscopy. The trivalent ions were shown to interact with the charged form of the carboxylic acid group from nanomolar concentrations (<300 nM). Analysis of the spectral features from both the symmetric and the asymmetric carboxylate modes reveals the presence of at least three distinct coordination structures linked to specific binding configurations. Although the same species were identified for both La 3+ and Y 3+ , they display a different concentration dependence, highlighting the ion-specificity of the interaction. From the analysis of the response of interfacial water molecules, the reversal of the surface charge, as well as the formation of yttrium hydroxide complexes, were detected upon increasing the amount of salt in solution. The binding interaction and kinetics of absorption are sensitive to the solution pH, showing a distinct ion speciation in the interfacial region when compared to the bulk. Changing the subphase pH or adding a monovalent background electrolyte that promotes deprotonation of the carboxylic acid headgroup could further improve the detection limit of La 3+ and Y 3+ to concentrations < 100 nM. These findings demonstrate that nM concentrations of trace metals contaminants, typically found on monovalent salts, can significantly influence the binding structure and kinetics in Langmuir monolayers.

01 COAL, LIGNITE, AND PEAT↗

DOE OSTI2021

Phase evolution during reactive flash sintering of Li 6.25 Al 0.25 La 3 Zr 2 O 12 starting from a chemically prepared powder

Here, reactive flash sintering (RFS) of a chemically prepared multiphase precursor powder was performed to fabricate Li 6.25 Al 0.25 La 3 Zr 2 O 12 (Al-LLZO) ceramics. This approach allowed for obtaining single-phase dense samples in a remarkably short processing time of 30 s, at a furnace temperature of 600 °C, with an electric field of 50 V cm -1 and a current limit of 150 mA mm -2 . The ceramics display high bulk conductivity of 0.18 mS cm -1 at room temperature. Furthermore, phase evolution is studied by in-situ X-ray diffraction during: i) conventional heating and ii) RFS under current rate mode. As expected, the intermediate phases progressively dissolved into the Al-LLZO matrix by conventional heating. On the other hand, RFS promoted the growth of the intermediate La 2 Zr 2 O 7 , an effect that was overcome by the thermally driven formation of Al-LLZO at higher temperatures. The observed different reaction pathway suggests that RFS can be used for stabilizing phases that are not thermodynamically favored upon conventional heating.

36 MATERIALS SCIENCE↗

DOE OSTI2026

Evaluation of high-temperature properties of binary, eutectic Ni-X alloys (X = B, Ca, Ce, La, Y, Zr)

We investigated the high-temperature behavior of binary eutectic nickel-base alloys with low-solubility elements, towards developing alloys with new combinations of structural and functional (e.g. thermal or corrosion) properties. Based on thermodynamic screening, we cast binary near-eutectic Ni-B, Ni-Ca, Ni-Ce, Ni-La, Ni-Y, and Ni-Zr alloys and characterized their microstructure and high-temperature properties. All alloys (except Ni-Ca) contain a fine eutectic microstructure, containing submicron alternating lamellae of γ-Ni and continuous intermetallic phases. The eutectic microstructure did not significantly coarsen at 700°C (except for Ni-B), but measurably coarsened in all alloys at 900°C, most quickly in Ni-B, followed by Ni-Ce, Ni-La, Ni-Y, and Ni-Zr. Coarsening in these alloys occurs by fault migration; diffusion within the intermetallic, and its interfacial energy, likely influence coarsening kinetics. At room-temperature, all alloys possess negligible ductility due to the continuous, brittle intermetallic. At 700 and 900°C, the Ni-Zr alloy showed the best combination of strength and ductility. Oxidation experiments at 900°C on Ni-Zr and Ni-Ce revealed heavy internal oxidation of the continuous intermetallic phase. Overall, the Ni-Zr alloy showed good high-temperature coarsening resistance and strength, though ductility and oxidation resistance require improvement for use in structural applications. Possible routes for improving alloy properties via additive manufacturing are discussed.

Ekaputra, Clement [ORNL] (ORCID:0000000307166479)↗