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Title: Eu{sub 3}F{sub 4}S{sub 2}: Synthesis, crystal structure, and magnetic properties of the mixed-valent europium(II,III) fluoride sulfide EuF{sub 2}.(EuFS){sub 2}

Abstract

Using the method to synthesize rare-earth metal(III) fluoride sulfides MFS (M=Y, La, Ce-Lu), in some cases we were able to obtain mixed-valent compounds such as Yb{sub 3}F{sub 4}S{sub 2} instead. With Eu{sub 3}F{sub 4}S{sub 2} another isotypic representative has now been synthesized. Eu{sub 3}F{sub 4}S{sub 2} (tetragonal, I4/mmm, a=400.34(2), c=1928.17(9) pm, Z=2) is obtained from the reaction of metallic europium, elemental sulfur, and europium trifluoride in a molar ratio of 5:6:4 within seven days at 850 deg. C in silica-jacketed gas-tightly sealed platinum ampoules. The single-phase product consists of black plate-shaped single crystals with a square cross section, which can be obtained from a flux using equimolar amounts of NaCl as fluxing agent. The crystal structure is best described as an intergrowth structure, in which one layer of CaF{sub 2}-type EuF{sub 2} is followed by two layers of PbFCl-type EuFS when sheeted parallel to the (001) plane. Accordingly there are two chemically and crystallographically different europium cations present. One of them (Eu{sup 2+}) is coordinated by eight fluoride anions in a cubic fashion, the other one (Eu{sup 3+}) exhibits a monocapped square antiprismatic coordination sphere with four F{sup -} and five S{sup 2-} anions. Although the structural ordering of themore » different charged europium cations is plausible, a certain amount of charge delocalization with some polaron activity has to take place, which is suggested by the black color of the title compound. Temperature dependent magnetic susceptibility measurements of Eu{sub 3}F{sub 4}S{sub 2} show Curie-Weiss behavior with an experimental magnetic moment of 8.19(5) mu{sub B} per formula unit and a paramagnetic Curie temperature of 0.3(2) K. No magnetic ordering is observed down to 4.2 K. In accordance with an ionic formula splitting like (Eu{sup II})(Eu{sup III}){sub 2}F{sub 4}S{sub 2} only one third of the europium centers in Eu{sub 3}F{sub 4}S{sub 2} carry permanent magnetic moments. {sup 151}Eu-Moessbauer spectroscopic experiments at 4.2 K show one signal at an isomer shift of -12.4(1) mm/s and a second one at 0.42(4) mm/s. These signals occur in a ratio of 1:2 and correspond to Eu{sup 2+} and Eu{sup 3+}, respectively. The spectra at 78 and 298 K are similar, thus no change in the Eu{sup 2+}/Eu{sup 3+} fraction can be detected. - Graphical abstract: Crystal structure and {sup 151}Eu-Moessbauer spectra of mixed-valent Eu{sub 3}F{sub 4}S{sub 2}.« less

Authors:
;  [1];  [2];  [2]; ;  [3];  [1]
  1. Institut fuer Anorganische Chemie, Universitaet Stuttgart, Pfaffenwaldring 55, 70569 Stuttgart (Germany)
  2. Institut fuer Anorganische und Analytische Chemie, Westfaelische Wilhelms-Universitaet Muenster, Corrensstrasse 30, 48149 Muenster (Germany)
  3. Institut fuer Physikalische Chemie, Westfaelische Wilhelms-Universitaet Muenster, Corrensstrasse 30, 48149 Muenster (Germany)
Publication Date:
OSTI Identifier:
21372388
Resource Type:
Journal Article
Resource Relation:
Journal Name: Journal of Solid State Chemistry; Journal Volume: 182; Journal Issue: 11; Other Information: DOI: 10.1016/j.jssc.2009.08.023; PII: S0022-4596(09)00408-3; Copyright (c) 2009 Elsevier Science B.V., Amsterdam, The Netherlands, All rights reserved.
Country of Publication:
United States
Language:
English
Subject:
36 MATERIALS SCIENCE; ANIONS; CATIONS; CURIE POINT; EUROPIUM FLUORIDES; EUROPIUM IONS; EUROPIUM SULFIDES; FLUORINE IONS; MAGNETIC MOMENTS; MAGNETIC SUSCEPTIBILITY; MOESSBAUER EFFECT; MONOCRYSTALS; PARAMAGNETISM; PLATINUM; SODIUM CHLORIDES; SULFUR IONS; TEMPERATURE RANGE 0000-0013 K; TEMPERATURE RANGE 0065-0273 K; TEMPERATURE RANGE 0273-0400 K; TETRAGONAL LATTICES; ALKALI METAL COMPOUNDS; CHALCOGENIDES; CHARGED PARTICLES; CHLORIDES; CHLORINE COMPOUNDS; CRYSTAL LATTICES; CRYSTAL STRUCTURE; CRYSTALS; ELEMENTS; EUROPIUM COMPOUNDS; FLUORIDES; FLUORINE COMPOUNDS; HALIDES; HALOGEN COMPOUNDS; IONS; MAGNETIC PROPERTIES; MAGNETISM; METALS; PHYSICAL PROPERTIES; PLATINUM METALS; RARE EARTH COMPOUNDS; SODIUM COMPOUNDS; SULFIDES; SULFUR COMPOUNDS; TEMPERATURE RANGE; THERMODYNAMIC PROPERTIES; TRANSITION ELEMENTS; TRANSITION TEMPERATURE

Citation Formats

Grossholz, Hagen, Hartenbach, Ingo, Kotzyba, Gunter, Poettgen, Rainer, E-mail: pottgen@uni-muenster.d, Trill, Henning, Mosel, Bernd D., and Schleid, Thomas, E-mail: schleid@iac.uni-stuttgart.d. Eu{sub 3}F{sub 4}S{sub 2}: Synthesis, crystal structure, and magnetic properties of the mixed-valent europium(II,III) fluoride sulfide EuF{sub 2}.(EuFS){sub 2}. United States: N. p., 2009. Web. doi:10.1016/j.jssc.2009.08.023.
Grossholz, Hagen, Hartenbach, Ingo, Kotzyba, Gunter, Poettgen, Rainer, E-mail: pottgen@uni-muenster.d, Trill, Henning, Mosel, Bernd D., & Schleid, Thomas, E-mail: schleid@iac.uni-stuttgart.d. Eu{sub 3}F{sub 4}S{sub 2}: Synthesis, crystal structure, and magnetic properties of the mixed-valent europium(II,III) fluoride sulfide EuF{sub 2}.(EuFS){sub 2}. United States. doi:10.1016/j.jssc.2009.08.023.
Grossholz, Hagen, Hartenbach, Ingo, Kotzyba, Gunter, Poettgen, Rainer, E-mail: pottgen@uni-muenster.d, Trill, Henning, Mosel, Bernd D., and Schleid, Thomas, E-mail: schleid@iac.uni-stuttgart.d. 2009. "Eu{sub 3}F{sub 4}S{sub 2}: Synthesis, crystal structure, and magnetic properties of the mixed-valent europium(II,III) fluoride sulfide EuF{sub 2}.(EuFS){sub 2}". United States. doi:10.1016/j.jssc.2009.08.023.
@article{osti_21372388,
title = {Eu{sub 3}F{sub 4}S{sub 2}: Synthesis, crystal structure, and magnetic properties of the mixed-valent europium(II,III) fluoride sulfide EuF{sub 2}.(EuFS){sub 2}},
author = {Grossholz, Hagen and Hartenbach, Ingo and Kotzyba, Gunter and Poettgen, Rainer, E-mail: pottgen@uni-muenster.d and Trill, Henning and Mosel, Bernd D. and Schleid, Thomas, E-mail: schleid@iac.uni-stuttgart.d},
abstractNote = {Using the method to synthesize rare-earth metal(III) fluoride sulfides MFS (M=Y, La, Ce-Lu), in some cases we were able to obtain mixed-valent compounds such as Yb{sub 3}F{sub 4}S{sub 2} instead. With Eu{sub 3}F{sub 4}S{sub 2} another isotypic representative has now been synthesized. Eu{sub 3}F{sub 4}S{sub 2} (tetragonal, I4/mmm, a=400.34(2), c=1928.17(9) pm, Z=2) is obtained from the reaction of metallic europium, elemental sulfur, and europium trifluoride in a molar ratio of 5:6:4 within seven days at 850 deg. C in silica-jacketed gas-tightly sealed platinum ampoules. The single-phase product consists of black plate-shaped single crystals with a square cross section, which can be obtained from a flux using equimolar amounts of NaCl as fluxing agent. The crystal structure is best described as an intergrowth structure, in which one layer of CaF{sub 2}-type EuF{sub 2} is followed by two layers of PbFCl-type EuFS when sheeted parallel to the (001) plane. Accordingly there are two chemically and crystallographically different europium cations present. One of them (Eu{sup 2+}) is coordinated by eight fluoride anions in a cubic fashion, the other one (Eu{sup 3+}) exhibits a monocapped square antiprismatic coordination sphere with four F{sup -} and five S{sup 2-} anions. Although the structural ordering of the different charged europium cations is plausible, a certain amount of charge delocalization with some polaron activity has to take place, which is suggested by the black color of the title compound. Temperature dependent magnetic susceptibility measurements of Eu{sub 3}F{sub 4}S{sub 2} show Curie-Weiss behavior with an experimental magnetic moment of 8.19(5) mu{sub B} per formula unit and a paramagnetic Curie temperature of 0.3(2) K. No magnetic ordering is observed down to 4.2 K. In accordance with an ionic formula splitting like (Eu{sup II})(Eu{sup III}){sub 2}F{sub 4}S{sub 2} only one third of the europium centers in Eu{sub 3}F{sub 4}S{sub 2} carry permanent magnetic moments. {sup 151}Eu-Moessbauer spectroscopic experiments at 4.2 K show one signal at an isomer shift of -12.4(1) mm/s and a second one at 0.42(4) mm/s. These signals occur in a ratio of 1:2 and correspond to Eu{sup 2+} and Eu{sup 3+}, respectively. The spectra at 78 and 298 K are similar, thus no change in the Eu{sup 2+}/Eu{sup 3+} fraction can be detected. - Graphical abstract: Crystal structure and {sup 151}Eu-Moessbauer spectra of mixed-valent Eu{sub 3}F{sub 4}S{sub 2}.},
doi = {10.1016/j.jssc.2009.08.023},
journal = {Journal of Solid State Chemistry},
number = 11,
volume = 182,
place = {United States},
year = 2009,
month =
}
  • La{sub 3}Fe{sub 2-{delta}}S{sub 7} (delta=0.042(6)) was synthesized through a reaction of the elements in a LiCl/KCl flux at 970 K, and its structure was determined by single-crystal X-ray diffraction. The compound crystallizes in the polar hexagonal space group P6{sub 3} with a=10.1906(6), c=5.9543(4) A and Z=2, and adopts the Ce{sub 6}Al{sub 10/3}S{sub 14} structure type. The structure contains both octahedral and tetrahedral iron sites: one-dimensional rods of face-sharing FeS{sub 6} octahedra run along the 6{sub 3} screw axis of the cell; FeS{sub 4} tetrahedra, all pointing in the same direction, are stacked along the threefold rotation axes. The iron-centered polyhedramore » are linked by lanthanum atoms, which are coordinated by [7+1] sulfur atoms in a bicapped trigonal prismatic arrangement. {sup 57}Fe Moessbauer spectroscopy confirms that Fe{sup III} and Fe{sup II} cations occupy the tetrahedral and octahedral iron sites, respectively. Magnetic susceptibility data indicate an antiferromagnetic transition at T{sub N}{approx}155 K. Density functional band structure calculations within the local density approximation reveal two covalent Fe-S subsystems within the compound that mix only weakly. A large anisotropy is indicated by bands that disperse predominantly along the hexagonal axis. The electronic band structure suggests pseudo-one-dimensional metallic conductivity along the rods of face-sharing FeS{sub 6} octahedra. However, due to the defects on the Fe{sup II} positions, La{sub 3}Fe{sub 2-{delta}}S{sub 7} shows an activated conducting behavior. - Graphical Abstract: Rods of face-sharing [Fe{sup II}S{sub 6}]-octahedra and [Fe{sup III}S{sub 4}]-tetrahedra, all pointing in the same direction, dominate the polar structure. Vacancies in the octahedral Fe positions downgrade one-dimensional metallic conductivity to an activated semi-conducting behavior.« less
  • EuPd{sub 3}S{sub 4} with a NaPt{sub 3}O{sub 4}-type structure was investigated by X-ray diffraction, {sup 151}Eu Moessbauer spectroscopy, magnetic susceptibility, and specific heat measurements. In this compound, Eu{sup 2+} and Eu{sup 3+} ions exist in the ratio of ca. 1:1. The Debye temperatures of Eu{sup 2+} and Eu{sup 3+} were determined to be 195 and 220 K, respectively. The isomer shift of Eu{sup 2+} in this EuPd{sub 3}S{sub 4} at 300 K is largest among Eu{sup 2+} sulfides because of the compression effect of the Eu{sup 2+} sites. The temperature dependence of the isomer shifts suggests that a hopping ofmore » the electron between Eu{sup 2+} and Eu{sup 3+} occurs in EuPd{sub 3}S{sub 4}. The Eu{sup 2+} ion was found to be in the antiferromagnetic state below 3 K from both the magnetic susceptibility and specific heat measurements.« less
  • One new manganese thiogermanate, [(dien){sub 2}Mn]Ge{sub 2}S{sub 4} (dien=diethylenetriamine), was prepared under mild solvothermal conditions and structurally and spectroscopically characterized. The title compound crystallizes in the orthorhombic system, chiral space group P2{sub 1}2{sub 1}2{sub 1} (no. 19) with a=9.113(4) Å, b=12.475(5) Å, c=17.077(7) Å, V=1941.5(15) Å{sup 3} and Z=4. Its structure features a three-dimensional (3D) network composed of a one-dimensional (1D) [Ge{sub 2}S{sub 4}]{sup 2−} anionic chain and a [(dien){sub 2}Mn]{sup 2+} complex interconnected via various hydrogen bonds. The most interesting structural feature of the compound is the presence of two different oxidation states of germanium centers in the 1Dmore » [Ge{sub 2}S{sub 4}]{sup 2−} chain, which is also supported by the result of X-ray photoelectron spectroscopy measurement. The optical property of the title compound has also been studied by UV–vis spectra. - Graphical abstract: One new thiogermanate, [(dien){sub 2}Mn]Ge{sub 2}S{sub 4}, contains a one-dimensional [Ge{sub 2}S{sub 4}]{sup 2−} anionic chain with two different oxidation states of germanium centers. Display Omitted - Highlights: • One new manganese thiogermanate [(dien){sub 2}Mn]Ge{sub 2}S{sub 4} was prepared. • The compound features 1D [Ge{sub 2}S{sub 4}]{sup 2−} chain composed of [Ge{sup II}S{sub 4}] and [Ge{sup IV}S{sub 4}] tetrahedra. • The first example of inorganic–organic hybrid thiogermanates with mixed valent Ge centers.« less
  • The reaction of NpO{sub 2} with SeO{sub 2} in the presence of CsCl at 180 {sup o}C results in the formation of Np(NpO{sub 2}){sub 2}(SeO{sub 3}){sub 3} (1). The structure of 1 consists of three crystallographically unique Np centers with three different coordination environments in two different oxidation states. Np(1) is found in a neptunyl(V), ONpO{sup +}, unit that is further ligated in the equatorial plane by three chelating SeO{sub 3}{sup 2-} anions to create a hexagonal bipyramidal NpO{sub 8} unit. A second neptunyl(V) cation also occurs for Np(2); it is bound by four bridging selenite anions and by themore » oxo atom from the Np(1) neptunyl cation to form a pentagonal bipyramidal, NpO{sub 7}, unit. The third neptunium center, Np(3), which contains Np(IV), is found in a distorted NpO{sub 8} dodecahedron. Np(3) is bound by five bridging selenite anions and by three neptunyl units via cation-cation interactions. The NpO{sub 7} pentagonal bipyramids and NpO{sub 8} hexagonal bipyramids share both corners and edges. Both of these polyhedra share corners via cation-cation interactions with the NpO{sub 8} dodecahedra creating a three-dimensional structure with small channels that house the stereochemically active lone pair of electrons on the selenite anions. Magnetic susceptibility data follow Curie-Weiss behavior over the entire temperature range measured (5 {<=} T {<=} 320 K). The effective moment, {mu}{sub eff} = 2.28 {mu}{sub B}, which represents an average over the three crystallographically inequivalent Np atoms, is within the expected range of values. There is no evidence of long-range ordering of the Np moments at temperatures down to 5 K, consistent with the negligible Weiss constant determined from fitting the susceptibility data. Crystallographic data: 1, orthorhombic, space group Pbca, a = 10.6216(5), b = 11.9695(6), and c = 17.8084(8) {angstrom} and Z = 8 (T = 193 K).« less
  • The new titanium borate was synthesized under high-pressure/high-temperature conditions in a Walker-type multianvil apparatus at 7.5 GPa and 1350 deg. C. Ti{sub 5}B{sub 12}O{sub 26} is built up exclusively from corner-sharing BO{sub 4}-tetrahedra and shows a structural relation to the Zintl phase NaTl. Consisting of B{sub 12}O{sub 26}-clusters as fundamental building blocks, the structure of Ti{sub 5}B{sub 12}O{sub 26} can be described via two interpenetrating diamond structures as in NaTl, where each atom corresponds to one B{sub 12}O{sub 26}-cluster. The tetragonal titanium borate crystallizes with eight formula units in the space group I4{sub 1}/acd and exhibits lattice parameters of a=1121.1(2)more » pm and c=2211.5(4) pm. Ti{sub 5}B{sub 12}O{sub 26} is a mixed-valent compound with Ti{sup III} and Ti{sup IV} cations. The environment of the titanium cations, as well as charge distribution calculations, leads us to the assumption that Ti{sup III} and Ti{sup IV} are located on different crystallographic sites. - Graphical abstract: High-pressure/high-temperature synthesis (multianvil technique) led to the first mixed-valent titanium borate Ti{sub 5}B{sub 12}O{sub 26}, which is exclusively built up from corner-sharing BO{sub 4}-tetrahedra, showing structural relations to the Zintl phase NaTl.« less