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Gd(OH)3 crystallizes in the hexagonal P6_3/m space group. The structure is three-dimensional. Gd3+ is bonded in a 9-coordinate geometry to nine equivalent O2- atoms. There are six shorter (2.47 Å) and three longer (2.49 Å) Gd–O bond lengths. H1+ is bonded in a single-bond geometry to one O2- atom. The H–O bond length is 0.97 Å. O2- is bonded in a single-bond geometry to three equivalent Gd3+ and one H1+ atom.
Gd(IO3)3 crystallizes in the monoclinic P2_1/c space group. The structure is three-dimensional. Gd3+ is bonded in a 8-coordinate geometry to eight O2- atoms. There are a spread of Gd–O bond distances ranging from 2.35–2.76 Å. There are nine inequivalent O2- sites. In the first O2- site, O2- is bonded in a distorted single-bond geometry to two I5+ atoms. There are one shorter (1.84 Å) and one longer (2.76 Å) O–I bond lengths. In the second O2- site, O2- is bonded in a 2-coordinate geometry to one Gd3+ and two I5+ atoms. There are one shorter (1.85 Å) and one longer (2.88 Å) O–I bond lengths. In the third O2- site, O2- is bonded in a bent 120 degrees geometry to one Gd3+ and one I5+ atom. The O–I bond length is 1.84 Å. In the fourth O2- site, O2- is bonded in a distorted bent 150 degrees geometry to one Gd3+ and one I5+ atom. The O–I bond length is 1.83 Å. In the fifth O2- site, O2- is bonded in a distorted water-like geometry to one Gd3+ and one I5+ atom. The O–I bond length is 1.84 Å. In the sixth O2- site, O2- is bonded in a 2-coordinate geometry to one Gd3+ and one I5+ atom. The O–I bond length is 1.85 Å. In the seventh O2- site, O2- is bonded in a distorted bent 150 degrees geometry to two equivalent Gd3+ and one I5+ atom. The O–I bond length is 1.86 Å. In the eighth O2- site, O2- is bonded in a 1-coordinate geometry to three I5+ atoms. There are a spread of O–I bond distances ranging from 1.87–2.74 Å. In the ninth O2- site, O2- is bonded in a distorted bent 120 degrees geometry to one Gd3+ and one I5+ atom. The O–I bond length is 1.84 Å. There are three inequivalent I5+ sites. In the first I5+ site, I5+ is bonded in a 6-coordinate geometry to six O2- atoms. In the second I5+ site, I5+ is bonded in a 3-coordinate geometry to three O2- atoms. In the third I5+ site, I5+ is bonded in a 3-coordinate geometry to four O2- atoms.
Gd(CoSi)2 crystallizes in the tetragonal I4/mmm space group. The structure is three-dimensional. Gd3+ is bonded in a distorted body-centered cubic geometry to eight equivalent Si4- atoms. All Gd–Si bond lengths are 3.04 Å. Co+2.50+ is bonded to four equivalent Si4- atoms to form a mixture of edge and corner-sharing CoSi4 tetrahedra. All Co–Si bond lengths are 2.28 Å. Si4- is bonded in a 9-coordinate geometry to four equivalent Gd3+, four equivalent Co+2.50+, and one Si4- atom. The Si–Si bond length is 2.54 Å.
Gd(PO3)3 crystallizes in the orthorhombic C222_1 space group. The structure is three-dimensional. Gd3+ is bonded in a 8-coordinate geometry to eight O2- atoms. There are a spread of Gd–O bond distances ranging from 2.34–2.69 Å. There are two inequivalent P5+ sites. In the first P5+ site, P5+ is bonded to four O2- atoms to form corner-sharing PO4 tetrahedra. There is two shorter (1.52 Å) and two longer (1.59 Å) P–O bond length. In the second P5+ site, P5+ is bonded to four O2- atoms to form corner-sharing PO4 tetrahedra. There are a spread of P–O bond distances ranging from 1.49–1.62 Å. There are five inequivalent O2- sites. In the first O2- site, O2- is bonded in a bent 150 degrees geometry to two equivalent P5+ atoms. In the second O2- site, O2- is bonded in a bent 150 degrees geometry to two P5+ atoms. In the third O2- site, O2- is bonded in a distorted bent 150 degrees geometry to one Gd3+ and one P5+ atom. In the fourth O2- site, O2- is bonded in a distorted linear geometry to one Gd3+ and one P5+ atom. In the fifth O2- site, O2- is bonded in a distorted single-bond geometry to two equivalent Gd3+ and one P5+ atom.
Gd(IO3)3 crystallizes in the monoclinic P2_1/c space group. The structure is three-dimensional. Gd3+ is bonded in a 8-coordinate geometry to eight O2- atoms. There are a spread of Gd–O bond distances ranging from 2.31–2.61 Å. There are nine inequivalent O2- sites. In the first O2- site, O2- is bonded in a distorted bent 120 degrees geometry to one Gd3+ and one I5+ atom. The O–I bond length is 1.83 Å. In the second O2- site, O2- is bonded in a distorted bent 150 degrees geometry to one Gd3+ and one I5+ atom. The O–I bond length is 1.84 Å. In the third O2- site, O2- is bonded in a bent 150 degrees geometry to one Gd3+ and one I5+ atom. The O–I bond length is 1.83 Å. In the fourth O2- site, O2- is bonded in a distorted single-bond geometry to one I5+ atom. The O–I bond length is 1.83 Å. In the fifth O2- site, O2- is bonded in a 2-coordinate geometry to one Gd3+ and one I5+ atom. The O–I bond length is 1.83 Å. In the sixth O2- site, O2- is bonded in a distorted bent 150 degrees geometry to one Gd3+ and one I5+ atom. The O–I bond length is 1.83 Å. In the seventh O2- site, O2- is bonded in a distorted bent 120 degrees geometry to one Gd3+ and one I5+ atom. The O–I bond length is 1.85 Å. In the eighth O2- site, O2- is bonded in a 1-coordinate geometry to one Gd3+ and one I5+ atom. The O–I bond length is 1.82 Å. In the ninth O2- site, O2- is bonded in a bent 150 degrees geometry to one Gd3+ and one I5+ atom. The O–I bond length is 1.81 Å. There are three inequivalent I5+ sites. In the first I5+ site, I5+ is bonded in a 3-coordinate geometry to three O2- atoms. In the second I5+ site, I5+ is bonded in a distorted trigonal non-coplanar geometry to three O2- atoms. In the third I5+ site, I5+ is bonded in a 3-coordinate geometry to three O2- atoms.
Gd(NiAs)2 crystallizes in the tetragonal I4/mmm space group. The structure is three-dimensional. Gd3+ is bonded in a distorted body-centered cubic geometry to eight equivalent As3- atoms. All Gd–As bond lengths are 3.14 Å. Ni+1.50+ is bonded to four equivalent As3- atoms to form a mixture of edge and corner-sharing NiAs4 tetrahedra. All Ni–As bond lengths are 2.36 Å. As3- is bonded in a 9-coordinate geometry to four equivalent Gd3+, four equivalent Ni+1.50+, and one As3- atom. The As–As bond length is 2.58 Å.
Gd(C2N3)3 crystallizes in the orthorhombic Cmcm space group. The structure is three-dimensional. Gd3+ is bonded in a 9-coordinate geometry to nine N3- atoms. There are a spread of Gd–N bond distances ranging from 2.48–2.87 Å. There are two inequivalent C4+ sites. In the first C4+ site, C4+ is bonded in a linear geometry to two N3- atoms. There is one shorter (1.18 Å) and one longer (1.30 Å) C–N bond length. In the second C4+ site, C4+ is bonded in a linear geometry to two N3- atoms. There is one shorter (1.18 Å) and one longer (1.31 Å) C–N bond length. There are four inequivalent N3- sites. In the first N3- site, N3- is bonded in a distorted bent 120 degrees geometry to one Gd3+ and two equivalent C4+ atoms. In the second N3- site, N3- is bonded in a distorted bent 150 degrees geometry to one Gd3+ and one C4+ atom. In the third N3- site, N3- is bonded in a distorted linear geometry to one Gd3+ and one C4+ atom. In the fourth N3- site, N3- is bonded in a bent 120 degrees geometry to one Gd3+ and two equivalent C4+ atoms.
Gd(BiO2)4 crystallizes in the triclinic P1 space group. The structure is three-dimensional. Gd3+ is bonded to seven O2- atoms to form distorted GdO7 pentagonal bipyramids that share a cornercorner with one BiO6 octahedra, edges with two equivalent BiO6 octahedra, edges with two equivalent GdO7 pentagonal bipyramids, and edges with two equivalent BiO7 pentagonal bipyramids. The corner-sharing octahedral tilt angles are 41°. There are a spread of Gd–O bond distances ranging from 2.34–2.47 Å. There are four inequivalent Bi+3.25+ sites. In the first Bi+3.25+ site, Bi+3.25+ is bonded to six O2- atoms to form BiO6 octahedra that share a cornercorner with one GdO7 pentagonal bipyramid, a cornercorner with one BiO7 pentagonal bipyramid, edges with two equivalent BiO6 octahedra, edges with two equivalent GdO7 pentagonal bipyramids, and edges with two equivalent BiO7 pentagonal bipyramids. There are a spread of Bi–O bond distances ranging from 2.23–2.34 Å. In the second Bi+3.25+ site, Bi+3.25+ is bonded to seven O2- atoms to form distorted BiO7 pentagonal bipyramids that share a cornercorner with one BiO6 octahedra, edges with two equivalent BiO6 octahedra, edges with two equivalent GdO7 pentagonal bipyramids, and edges with two equivalent BiO7 pentagonal bipyramids. The corner-sharing octahedral tilt angles are 48°. There are a spread of Bi–O bond distances ranging from 2.35–2.61 Å. In the third Bi+3.25+ site, Bi+3.25+ is bonded in a 6-coordinate geometry to six O2- atoms. There are a spread of Bi–O bond distances ranging from 2.23–2.55 Å. In the fourth Bi+3.25+ site, Bi+3.25+ is bonded in a 6-coordinate geometry to six O2- atoms. There are a spread of Bi–O bond distances ranging from 2.23–2.55 Å. There are eight inequivalent O2- sites. In the first O2- site, O2- is bonded to two equivalent Gd3+ and two Bi+3.25+ atoms to form OGd2Bi2 tetrahedra that share corners with thirteen OGd2Bi2 tetrahedra and edges with five OGdBi3 tetrahedra. In the second O2- site, O2- is bonded to one Gd3+ and three Bi+3.25+ atoms to form a mixture of distorted edge and corner-sharing OGdBi3 tetrahedra. In the third O2- site, O2- is bonded to four Bi+3.25+ atoms to form distorted OBi4 tetrahedra that share corners with thirteen OGd2Bi2 tetrahedra and edges with four OGdBi3 tetrahedra. In the fourth O2- site, O2- is bonded to one Gd3+ and three Bi+3.25+ atoms to form distorted OGdBi3 tetrahedra that share corners with thirteen OGd2Bi2 tetrahedra and edges with five OBi4 tetrahedra. In the fifth O2- site, O2- is bonded to one Gd3+ and three Bi+3.25+ atoms to form OGdBi3 tetrahedra that share corners with eleven OGd2Bi2 tetrahedra and edges with five OBi4 tetrahedra. In the sixth O2- site, O2- is bonded to four Bi+3.25+ atoms to form OBi4 tetrahedra that share corners with eleven OGd2Bi2 tetrahedra and edges with five OGdBi3 tetrahedra. In the seventh O2- site, O2- is bonded to four Bi+3.25+ atoms to form OBi4 tetrahedra that share corners with fourteen OGd2Bi2 tetrahedra and edges with four OGdBi3 tetrahedra. In the eighth O2- site, O2- is bonded to two equivalent Gd3+ and two Bi+3.25+ atoms to form distorted OGd2Bi2 tetrahedra that share corners with fourteen OGd2Bi2 tetrahedra and edges with four OGdBi3 tetrahedra.
Gd(CuS)3 crystallizes in the trigonal R-3 space group. The structure is three-dimensional. Gd3+ is bonded to six equivalent S2- atoms to form GdS6 octahedra that share corners with twelve equivalent CuS4 tetrahedra, edges with three equivalent GdS6 octahedra, and edges with six equivalent CuS4 tetrahedra. There are three shorter (2.78 Å) and three longer (2.79 Å) Gd–S bond lengths. Cu1+ is bonded to four equivalent S2- atoms to form CuS4 tetrahedra that share corners with four equivalent GdS6 octahedra, corners with six equivalent CuS4 tetrahedra, edges with two equivalent GdS6 octahedra, and edges with three equivalent CuS4 tetrahedra. The corner-sharing octahedra tilt angles range from 17–54°. There are three shorter (2.38 Å) and one longer (2.43 Å) Cu–S bond lengths. S2- is bonded in a 6-coordinate geometry to two equivalent Gd3+ and four equivalent Cu1+ atoms.
Gd(Ni2B)6 crystallizes in the orthorhombic Cmc2_1 space group. The structure is three-dimensional. Gd3+ is bonded in a distorted hexagonal planar geometry to six B3- atoms. There are a spread of Gd–B bond distances ranging from 2.99–3.29 Å. There are seven inequivalent Ni+1.25+ sites. In the first Ni+1.25+ site, Ni+1.25+ is bonded in a distorted T-shaped geometry to three B3- atoms. There are two shorter (2.10 Å) and one longer (2.18 Å) Ni–B bond lengths. In the second Ni+1.25+ site, Ni+1.25+ is bonded in a T-shaped geometry to three B3- atoms. There are two shorter (2.00 Å) and one longer (2.08 Å) Ni–B bond lengths. In the third Ni+1.25+ site, Ni+1.25+ is bonded to four B3- atoms to form a mixture of edge and corner-sharing NiB4 tetrahedra. There are a spread of Ni–B bond distances ranging from 1.98–2.09 Å. In the fourth Ni+1.25+ site, Ni+1.25+ is bonded in a T-shaped geometry to three B3- atoms. There are a spread of Ni–B bond distances ranging from 2.03–2.10 Å. In the fifth Ni+1.25+ site, Ni+1.25+ is bonded to four B3- atoms to form a mixture of edge and corner-sharing NiB4 tetrahedra. There are a spread of Ni–B bond distances ranging from 2.02–2.09 Å. In the sixth Ni+1.25+ site, Ni+1.25+ is bonded to four B3- atoms to form a mixture of distorted edge and corner-sharing NiB4 tetrahedra. There are a spread of Ni–B bond distances ranging from 2.02–2.10 Å. In the seventh Ni+1.25+ site, Ni+1.25+ is bonded in a distorted T-shaped geometry to three B3- atoms. There are a spread of Ni–B bond distances ranging from 2.05–2.13 Å. There are four inequivalent B3- sites. In the first B3- site, B3- is bonded in a 7-coordinate geometry to one Gd3+ and seven Ni+1.25+ atoms. In the second B3- site, B3- is bonded in a 9-coordinate geometry to one Gd3+ and seven Ni+1.25+ atoms. In the third B3- site, B3- is bonded in a 7-coordinate geometry to one Gd3+ and seven Ni+1.25+ atoms. In the fourth B3- site, B3- is bonded in a 7-coordinate geometry to one Gd3+ and seven Ni+1.25+ atoms.
Gd(OsB)2 crystallizes in the orthorhombic Fddd space group. The structure is three-dimensional. Gd3+ is bonded in a 4-coordinate geometry to four equivalent Os+1.50- atoms. All Gd–Os bond lengths are 3.02 Å. Os+1.50- is bonded in a 4-coordinate geometry to two equivalent Gd3+ and four equivalent B atoms. There are two shorter (2.08 Å) and two longer (2.18 Å) Os–B bond lengths. B is bonded in a 4-coordinate geometry to four equivalent Os+1.50- atoms.
Gd(AlC)3 crystallizes in the hexagonal P6_3/mmc space group. The structure is three-dimensional. Gd3+ is bonded to six equivalent C4- atoms to form GdC6 octahedra that share corners with six equivalent AlC4 tetrahedra, edges with six equivalent GdC6 octahedra, and edges with six equivalent AlC4 tetrahedra. All Gd–C bond lengths are 2.59 Å. There are two inequivalent Al3+ sites. In the first Al3+ site, Al3+ is bonded to four C4- atoms to form AlC4 tetrahedra that share corners with three equivalent GdC6 octahedra, corners with seven equivalent AlC4 tetrahedra, and edges with three equivalent GdC6 octahedra. The corner-sharing octahedral tilt angles are 20°. There are one shorter (2.02 Å) and three longer (2.11 Å) Al–C bond lengths. In the second Al3+ site, Al3+ is bonded in a trigonal planar geometry to three equivalent C4- atoms. All Al–C bond lengths are 1.99 Å. There are two inequivalent C4- sites. In the first C4- site, C4- is bonded in a 6-coordinate geometry to three equivalent Gd3+ and three equivalent Al3+ atoms. In the second C4- site, C4- is bonded to five Al3+ atoms to form corner-sharing CAl5 trigonal bipyramids.
Mixtures of Ce-doped rare-earth aluminum perovskites are drawing a significant amount of attention as potential scintillating devices. However, the synthesis of complex perovskite systems leads to many challenges. Designing the A-site cations with an equiatomic ratio allows for the stabilization of a single-crystal phase driven by an entropic regime. This work describes the synthesis of a highly epitaxial thin film of configurationally disordered rare-earth aluminum perovskite oxide (La 0.2 Lu 0.2 Y 0.2 Gd 0.2 Ce 0.2 )AlO 3 and characterizes the structural and optical properties. The thin films exhibit three equivalent epitaxial domains having an orthorhombic structure resulting from monoclinic distortion of the perovskite cubic cell. An excitation of 286.5 nm from Gd 3+ and energy transfer to Ce 3+ with 405 nm emission are observed, which represents the potential for high-energy conversion. These experimental results also offer the pathway to tunable optical properties of high-entropy rare-earth epitaxial perovskite films for a range of applications.
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.
Achieving multimodal luminescence within a single phosphor is vital for multifunctional applications but remains challenging due to complex color tuning and trap engineering. In this study, we report Pr 3+ and Gd 3+ co‐doped LaAlO 3 (LAO:PG) phosphors, designed through careful modulation of multilevel traps and Pr 3+ → Gd 3+ energy transfer dynamics. These materials exhibit diverse luminescence modes, including down‐conversion luminescence (DCL), up‐conversion luminescence (UCL), persistent luminescence (PersL), optically stimulated luminescence (OSL), and thermally stimulated luminescence (TSL) across a wide spectral range. Unlike previously studied Pr 3+ ‐doped LAO, the co‐doped LAO:PG shows DCL in both UV‐visible and NIR regions and displays ultraviolet‐C UCL under visible excitation. Notably, we observe, for the first time, PersL lasting several minutes in these phosphors—an improvement over the non‐PersL behavior of Pr 3+ ‐only doped LAO. Additionally, the LAO:PG phosphors exhibit strong OSL response. TSL analysis reveals five distinct trap levels linked to these properties. Density functional theory calculations further correlate intrinsic defects to these traps, supporting a proposed mechanism for the observed multimodal luminescence. These findings highlight LAO:PG as a promising platform for developing advanced phosphors with integrated luminescence modes, paving the way for future applications in data storage, phototherapy, and anti‐counterfeiting technologies.
The cathode activity in a solid oxide fuel cell can be promoted by introducing various catalysts to reduce its polarization resistance towards oxygen reduction, and thus improve cell performance. Here, in this work, the La 0.6 Sr 0.4 Co 0.2 Fe 0.8 O 3 (LSCF) cathode surface is modified by the infiltration of Pr 6 O 11 and the power density at 0.8 V and 750 °C is improved by 21%. Moreover, by replacing the traditional barrier layer Gd 0.2 Ce 0.8 O 1.9 with mixed conducting Pr 0.1 Gd 0.1 Ce 0.8 O 1.9 (PGCO), the power density increases by 38%. The ohmic resistance is dramatically reduced by applying the PGCO interlayer. The distribution of relaxation time was used to analyze the mechanism for which the polarization resistance was decreased, attributing to the mixed conduction nature in PrO x . An increase of power density, ~0.358 W/cm 2 (71%) at 0.8 V, is achieved with the implementation of both surface modification and buffer layer engineering.
In this work, crystal structure and magnetic properties of the quaternary Gd 4 Nd 1 Si 2 Ge 2 compound were investigated using synchrotron X-ray diffraction and magnetic measurements. The compound crystallized into an orthorhombic structure in the temperature range 200-300 K. In zero field cooling, the compound undergoes a spin reorientation following a ferromagnetic-like transition at 276 K. The spin reorientation is hinted at by nonlinear changes of lattice parameters but is suppressed in a high magnetic field of 6 T. Magnetic measurements revealed a magnetocaloric effect with a high relative cooling power. It is suggested that Nd substitution for Gd enlarges magnetic anisotropy and induces a canted spin structure.
Growing interest in next generation molten salt nuclear reactors necessitates a fundamental understanding of the chemical and physico-chemical properties of fission products, including elements of the lanthanide series. In this study, we probed coordination environment of Eu, Gd, Tb, and Dy in their chloride salts with both laboratory and synchrotron scale X-ray absorption spectroscopy (XAS). Here the aerobic melting was carried out with LnCl 3 ·nH 2 O, where Ln is Eu, Gd, Tb, and Dy, and yielded predominant formation of oxychlorides (LnOCl), that was confirmed by extended X-ray absorption fine structure (EXAFS) analysis and X-ray diffraction (XRD). Density functional theory (DFT) and time-dependent density functional theory (TDDFT) computations were performed to obtain ground state structures, lattice parameters, and to simulate L 3 -edge XANES (X-ray absorption near edge structure) spectra of the LnCl 3 ·nH 2 O and LnOCl. A blue shift, initially predicted by our calculations, was also observed for the experimental Ln L 3 -edge XANES spectra of the hydrated trichlorides vs oxychlorides, highlighting the power of combining the predictive ability of theory with experiment to elucidate the properties of the compounds of interest. The blue shift is indicative of structural stabilization of LnCl 3 ·nH 2 O due to higher symmetry compared with LnOCl. To the best of knowledge, this is a first study providing the framework for fundamental insights into the structure of Ln trichlorides and oxychlorides in support of future characterization of lanthanides in the molten salt environment.