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At least 73 records · Page 4
All sourcesNASA NTRSDOE OSTI
DOE OSTI2020

Materials Data on Pr(BIr)2 by Materials Project

Pr(IrB)2 is alpha Pu-derived structured and crystallizes in the orthorhombic Fddd space group. The structure is three-dimensional. Pr is bonded in a 10-coordinate geometry to eight equivalent Ir and six equivalent B atoms. There are four shorter (3.09 Å) and four longer (3.32 Å) Pr–Ir bond lengths. There are two shorter (3.05 Å) and four longer (3.16 Å) Pr–B bond lengths. Ir is bonded in a 4-coordinate geometry to four equivalent Pr and four equivalent B atoms. There are two shorter (2.10 Å) and two longer (2.18 Å) Ir–B bond lengths. B is bonded in a 4-coordinate geometry to three equivalent Pr and four equivalent Ir atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Pr(Mg4Al3)4 by Materials Project

Pr(Mg4Al3)4 crystallizes in the cubic I-43m space group. The structure is three-dimensional. there are two inequivalent Mg sites. In the first Mg site, Mg is bonded in a 10-coordinate geometry to three equivalent Mg, one Pr, and six equivalent Al atoms. All Mg–Mg bond lengths are 3.02 Å. The Mg–Pr bond length is 3.33 Å. All Mg–Al bond lengths are 3.22 Å. In the second Mg site, Mg is bonded in a 12-coordinate geometry to seven Mg and five equivalent Al atoms. There are two shorter (3.11 Å) and four longer (3.18 Å) Mg–Mg bond lengths. There are a spread of Mg–Al bond distances ranging from 2.85–3.18 Å. Pr is bonded in a 12-coordinate geometry to four equivalent Mg and twelve equivalent Al atoms. All Pr–Al bond lengths are 3.27 Å. Al is bonded in a 11-coordinate geometry to seven Mg, one Pr, and three equivalent Al atoms. There are one shorter (2.76 Å) and two longer (2.80 Å) Al–Al bond lengths.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Pr(BRh)4 by Materials Project

Pr(RhB)4 crystallizes in the tetragonal P4_2/nmc space group. The structure is three-dimensional. Pr is bonded in a 12-coordinate geometry to twelve equivalent Rh and twelve equivalent B atoms. There are four shorter (3.02 Å) and eight longer (3.21 Å) Pr–Rh bond lengths. There are eight shorter (3.07 Å) and four longer (3.18 Å) Pr–B bond lengths. Rh is bonded in a 5-coordinate geometry to three equivalent Pr and five equivalent B atoms. There are a spread of Rh–B bond distances ranging from 2.24–2.28 Å. B is bonded in a 6-coordinate geometry to three equivalent Pr, five equivalent Rh, and one B atom. The B–B bond length is 1.82 Å.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Pr(Ge2Rh3)2 by Materials Project

Pr(Rh3Ge2)2 crystallizes in the hexagonal P-6m2 space group. The structure is three-dimensional. Pr is bonded to six equivalent Rh and six equivalent Ge atoms to form face-sharing PrGe6Rh6 cuboctahedra. All Pr–Rh bond lengths are 3.19 Å. All Pr–Ge bond lengths are 3.17 Å. There are two inequivalent Rh sites. In the first Rh site, Rh is bonded in a 5-coordinate geometry to five Ge atoms. There are one shorter (2.51 Å) and four longer (2.58 Å) Rh–Ge bond lengths. In the second Rh site, Rh is bonded in a 6-coordinate geometry to two equivalent Pr and four Ge atoms. There are two shorter (2.50 Å) and two longer (2.57 Å) Rh–Ge bond lengths. There are two inequivalent Ge sites. In the first Ge site, Ge is bonded in a 9-coordinate geometry to nine Rh atoms. In the second Ge site, Ge is bonded in a 8-coordinate geometry to two equivalent Pr and six Rh atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Pr(Sn2Rh)2 by Materials Project

Pr(RhSn2)2 crystallizes in the orthorhombic Pnma space group. The structure is three-dimensional. Pr is bonded in a 6-coordinate geometry to seven Sn atoms. There are a spread of Pr–Sn bond distances ranging from 3.20–3.39 Å. There are two inequivalent Rh sites. In the first Rh site, Rh is bonded in a 7-coordinate geometry to seven Sn atoms. There are a spread of Rh–Sn bond distances ranging from 2.72–2.90 Å. In the second Rh site, Rh is bonded in a 7-coordinate geometry to seven Sn atoms. There are a spread of Rh–Sn bond distances ranging from 2.73–2.85 Å. There are four inequivalent Sn sites. In the first Sn site, Sn is bonded in a 6-coordinate geometry to two equivalent Pr and four Rh atoms. In the second Sn site, Sn is bonded in a 5-coordinate geometry to two equivalent Pr and three equivalent Rh atoms. In the third Sn site, Sn is bonded in a 3-coordinate geometry to three equivalent Pr and three equivalent Rh atoms. In the fourth Sn site, Sn is bonded to four Rh atoms to form a mixture of distorted corner and edge-sharing SnRh4 tetrahedra.

36 MATERIALS SCIENCE↗
DOE OSTI2021

Searching for a route to synthesize in situ epitaxial Pr 2 Ir 2 O 7 thin films with thermodynamic methods

In situ growth of pyrochlore iridate thin films has been a long-standing challenge due to the low reactivity of Ir at low temperatures and the vaporization of volatile gas species such as IrO 3 (g) and IrO 2 (g) at high temperatures and high P O2 . To address this challenge, we combine thermodynamic analysis of the Pr-Ir-O 2 system with experimental results from the conventional physical vapor deposition (PVD) technique of co-sputtering. Our results indicate that only high growth temperatures yield films with crystallinity sufficient for utilizing and tailoring the desired topological electronic properties and the in situ synthesis of Pr 2 Ir 2 O 7 thin films is fettered by the inability to grow with P O2 on the order of 10 Torr at high temperatures, a limitation inherent to the PVD process. Thus, we suggest techniques capable of supplying high partial pressure of key species during deposition, in particular chemical vapor deposition (CVD), as a route to synthesis of Pr 2 Ir 2 O 7 .

Chemistry↗
DOE OSTI2021

Complex magnetic properties associated with competing local and itinerant magnetism in \({\text {Pr}}_2 {\text {Co}}_{0.86} {\text {Si}}_{2.88}\)

Ternary intermetallic compound \({\text {Pr}}_2 {\text {Co}}_{0.86} {\text {Si}}_{2.88}\) has been synthesized in single phase and characterized by x-ray diffraction, scanning electron microscopy with energy dispersive x-ray spectroscopy (SEM-EDX) analysis, magnetization, heat capacity, neutron diffraction and muon spin rotation/relaxation ( \(\mu\) SR) measurements. The polycrystalline compound was synthesized in single phase by introducing necessary vacancies in Co/Si sites. Magnetic, heat capacity, and zero-field neutron diffraction studies reveal that the system undergoes magnetic transition below \(\sim\) 4 K. Neutron diffraction measurement further reveals that the magnetic ordering is antiferromagnetic in nature with an weak ordered moment. The high temperature magnetic phase has been attributed to glassy in nature consisting of ferromagnetic clusters of itinerant (3 d ) Co moments as evident by the development of internal field in zero-field \(\mu\) SR below 50 K. The density-functional theory (DFT) calculations suggest that the low temperature magnetic transition is associated with antiferromagnetic coupling between Pr 4 f and Co 3 d spins. Pr moments show spin fluctuation along with unconventional orbital moment quenching due to crystal field. The evolution of the symmetry and the crystalline electric field environment of Pr-ions are also studied and compared theoretically between the elemental Pr and when it is coupled with other elements such as Co. The localized moment of Pr 4 f and itinerant moment of Co 3 d compete with each other below \(\sim\) 20 K resulting in an unusual temperature dependence of magnetic coercivity in the system.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Pr(FeGe)2 by Materials Project

PrFe2Ge2 crystallizes in the tetragonal I4/mmm space group. The structure is three-dimensional. Pr is bonded in a 8-coordinate geometry to eight equivalent Fe and eight equivalent Ge atoms. All Pr–Fe bond lengths are 3.38 Å. All Pr–Ge bond lengths are 3.16 Å. Fe is bonded to four equivalent Pr and four equivalent Ge atoms to form a mixture of distorted corner, edge, and face-sharing FePr4Ge4 tetrahedra. All Fe–Ge bond lengths are 2.45 Å. Ge is bonded in a 9-coordinate geometry to four equivalent Pr, four equivalent Fe, and one Ge atom. The Ge–Ge bond length is 2.65 Å.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Pr(GeRh)2 by Materials Project

PrRh2Ge2 crystallizes in the tetragonal I4/mmm space group. The structure is three-dimensional. Pr is bonded in a 8-coordinate geometry to eight equivalent Rh and eight equivalent Ge atoms. All Pr–Rh bond lengths are 3.38 Å. All Pr–Ge bond lengths are 3.25 Å. Rh is bonded to four equivalent Pr and four equivalent Ge atoms to form a mixture of distorted corner, edge, and face-sharing RhPr4Ge4 tetrahedra. All Rh–Ge bond lengths are 2.48 Å. Ge is bonded in a 9-coordinate geometry to four equivalent Pr, four equivalent Rh, and one Ge atom. The Ge–Ge bond length is 2.65 Å.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Pr(ClO4)3 by Materials Project

Pr(ClO4)3 crystallizes in the hexagonal P6_3/m space group. The structure is three-dimensional. Pr is bonded in a 9-coordinate geometry to nine O atoms. There are six shorter (2.50 Å) and three longer (2.57 Å) Pr–O bond lengths. There are three inequivalent O sites. In the first O site, O is bonded in a single-bond geometry to one Cl atom. The O–Cl bond length is 1.42 Å. In the second O site, O is bonded in a bent 150 degrees geometry to one Pr and one Cl atom. The O–Cl bond length is 1.47 Å. In the third O site, O is bonded in a distorted bent 150 degrees geometry to one Pr and one Cl atom. The O–Cl bond length is 1.47 Å. Cl is bonded in a tetrahedral geometry to four O atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Pr(SiRh)2 by Materials Project

PrRh2Si2 crystallizes in the tetragonal I4/mmm space group. The structure is three-dimensional. Pr is bonded in a 8-coordinate geometry to eight equivalent Rh and eight equivalent Si atoms. All Pr–Rh bond lengths are 3.29 Å. All Pr–Si bond lengths are 3.19 Å. Rh is bonded to four equivalent Pr and four equivalent Si atoms to form a mixture of distorted face, edge, and corner-sharing RhPr4Si4 tetrahedra. All Rh–Si bond lengths are 2.43 Å. Si is bonded in a 9-coordinate geometry to four equivalent Pr, four equivalent Rh, and one Si atom. The Si–Si bond length is 2.57 Å.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Pr(CuGe)2 by Materials Project

PrCu2Ge2 crystallizes in the tetragonal I4/mmm space group. The structure is three-dimensional. Pr is bonded in a 8-coordinate geometry to eight equivalent Cu and eight equivalent Ge atoms. All Pr–Cu bond lengths are 3.32 Å. All Pr–Ge bond lengths are 3.21 Å. Cu is bonded in a 4-coordinate geometry to four equivalent Pr and four equivalent Ge atoms. All Cu–Ge bond lengths are 2.46 Å. Ge is bonded in a 9-coordinate geometry to four equivalent Pr, four equivalent Cu, and one Ge atom. The Ge–Ge bond length is 2.54 Å.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Pr(AgGe)2 by Materials Project

PrAg2Ge2 crystallizes in the tetragonal I4/mmm space group. The structure is three-dimensional. Pr is bonded in a 8-coordinate geometry to eight equivalent Ag and eight equivalent Ge atoms. All Pr–Ag bond lengths are 3.53 Å. All Pr–Ge bond lengths are 3.31 Å. Ag is bonded to four equivalent Pr, four equivalent Ag, and four equivalent Ge atoms to form a mixture of distorted corner, edge, and face-sharing AgPr4Ag4Ge4 cuboctahedra. All Ag–Ag bond lengths are 3.07 Å. All Ag–Ge bond lengths are 2.67 Å. Ge is bonded in a 9-coordinate geometry to four equivalent Pr, four equivalent Ag, and one Ge atom. The Ge–Ge bond length is 2.47 Å.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Pr(GeRu)2 by Materials Project

PrRu2Ge2 crystallizes in the tetragonal I4/mmm space group. The structure is three-dimensional. Pr is bonded in a 8-coordinate geometry to eight equivalent Ru and eight equivalent Ge atoms. All Pr–Ru bond lengths are 3.32 Å. All Pr–Ge bond lengths are 3.34 Å. Ru is bonded in a 4-coordinate geometry to four equivalent Pr and four equivalent Ge atoms. All Ru–Ge bond lengths are 2.46 Å. Ge is bonded in a 9-coordinate geometry to four equivalent Pr, four equivalent Ru, and one Ge atom. The Ge–Ge bond length is 2.71 Å.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Pr(PRu)2 by Materials Project

PrRu2P2 crystallizes in the tetragonal I4/mmm space group. The structure is three-dimensional. Pr is bonded in a 8-coordinate geometry to eight equivalent Ru and eight equivalent P atoms. All Pr–Ru bond lengths are 3.26 Å. All Pr–P bond lengths are 3.19 Å. Ru is bonded in a 12-coordinate geometry to four equivalent Pr and four equivalent P atoms. All Ru–P bond lengths are 2.36 Å. P is bonded in a 9-coordinate geometry to four equivalent Pr, four equivalent Ru, and one P atom. The P–P bond length is 2.74 Å.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Pr(NiGe)2 by Materials Project

PrNi2Ge2 crystallizes in the tetragonal I4/mmm space group. The structure is three-dimensional. Pr is bonded in a 8-coordinate geometry to eight equivalent Ni and eight equivalent Ge atoms. All Pr–Ni bond lengths are 3.23 Å. All Pr–Ge bond lengths are 3.22 Å. Ni is bonded in a 4-coordinate geometry to four equivalent Pr and four equivalent Ge atoms. All Ni–Ge bond lengths are 2.38 Å. Ge is bonded in a 9-coordinate geometry to four equivalent Pr, four equivalent Ni, and one Ge atom. The Ge–Ge bond length is 2.63 Å.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Pr(PPd)2 by Materials Project

PrPd2P2 crystallizes in the tetragonal I4/mmm space group. The structure is three-dimensional. Pr is bonded in a 8-coordinate geometry to eight equivalent Pd and eight equivalent P atoms. All Pr–Pd bond lengths are 3.27 Å. All Pr–P bond lengths are 3.17 Å. Pd is bonded to four equivalent Pr and four equivalent P atoms to form a mixture of distorted corner, edge, and face-sharing PdPr4P4 cuboctahedra. All Pd–P bond lengths are 2.50 Å. P is bonded in a 9-coordinate geometry to four equivalent Pr, four equivalent Pd, and one P atom. The P–P bond length is 2.27 Å.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Pr(ClO)3 by Materials Project

PrOCl3O2 crystallizes in the orthorhombic Pnma space group. The structure is two-dimensional and consists of four hydrogen peroxide molecules and two PrOCl3 sheets oriented in the (0, 0, 1) direction. In each PrOCl3 sheet, Pr is bonded in a 6-coordinate geometry to two equivalent O and four equivalent Cl atoms. There are one shorter (2.34 Å) and one longer (2.40 Å) Pr–O bond lengths. There are two shorter (2.84 Å) and two longer (2.85 Å) Pr–Cl bond lengths. O is bonded in a trigonal planar geometry to two equivalent Pr and one Cl atom. The O–Cl bond length is 1.69 Å. There are two inequivalent Cl sites. In the first Cl site, Cl is bonded in a water-like geometry to two equivalent Pr atoms. In the second Cl site, Cl is bonded in a single-bond geometry to one O atom.

36 MATERIALS SCIENCE↗