Author: Eiken Haussühl

Phase transition of tetragonal copper sulfide Cu2S at low temperatures

2017

The low-temperature behavior of tetragonal copper sulfide, ${\mathrm{Cu}}_{2}\mathrm{S}$, was investigated by powder and single-crystal x-ray diffraction, calorimetry, electrical resistance measurements, and ambient temperature optical absorption spectroscopy. The experiments were complemented by density-functional-theory-based calculations. High-quality, polycrystalline samples and single crystals of tetragonal copper sulfide were synthesized at 5 GPa and 700 K in a large volume multianvil press. Tetragonal ${\mathrm{Cu}}_{2}\mathrm{S}$ undergoes a temperature-induced phase transition to an orthorhombic structure at around 202 K with a hysteresis of $\ifmmode\pm\else\textpm\fi{}21$ K, an e…

Phase transitionMaterials scienceAbsorption spectroscopyBand gapTransition temperaturechemistry.chemical_element02 engineering and technology010402 general chemistry021001 nanoscience & nanotechnology01 natural sciencesCopperHeat capacity0104 chemical sciencesCrystallographyTetragonal crystal systemchemistryOrthorhombic crystal system0210 nano-technologyPhysical Review B

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Irradiation effects in CaF2probed by Raman scattering

2016

The formation conditions and dynamics of Ca colloids and point defects that appear in irradiated single crystals of CaF2 were investigated by Raman spectroscopy. The intensity changes in the Raman spectra because of the presence of different concentrations of point defects and Ca colloids that emerged in CaF2 after irradiation with 2.2 GeV Au ions were used to study their distribution and stability under illumination with three laser wavelengths (473, 532 and 633 nm) at different output powers (2 to 200 mW). A damage saturation at a fluence of 6 × 1011 ion cm−2 was observed. The dependence of the spectral changes on the ion fluence can be described by a core/halo damage cross-section model.…

010302 applied physicsChemistryAnalytical chemistry02 engineering and technology021001 nanoscience & nanotechnologyLaser01 natural sciencesCrystallographic defectMolecular physicsFluencelaw.inventionIonsymbols.namesakeSwift heavy ionlaw0103 physical sciencessymbolsGeneral Materials ScienceIrradiation0210 nano-technologyRaman spectroscopySpectroscopyRaman scatteringJournal of Raman Spectroscopy

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High-pressure study of substrate material ScAlMgO4

2011

We report on the structural properties of ScAlMgO4 studied under quasi-hydrostatic pressure using synchrotron high-pressure x-ray diffraction up to 40 GPa. We also report on single-crystal studies of ScAlMgO4 performed at 300 K and 100 K. We found that the low-pressure phase remains stable up to 24 GPa. At 28 GPa, we detected a reversible phase transformation. The high-pressure phase is assigned to a monoclinic distortion of the low-pressure phase. No additional phase transition is observed up to 40 GPa. In addition, the equation of state, compressibility tensor, and thermal expansion coefficients of ScAlMgO4 are determined. The bulk modulus of ScAlMgO4 is found to be 143(8) GPa, with a str…

Chemical Physics (physics.chem-ph)Condensed Matter - Materials SciencePhase transitionBulk modulusMaterials scienceCondensed matter physicsMaterials Science (cond-mat.mtrl-sci)FOS: Physical sciencesCondensed Matter PhysicsThermal expansionElectronic Optical and Magnetic MaterialsCondensed Matter::Materials SciencePhysics - Chemical PhysicsX-ray crystallographyCompressibilityAnisotropyMonoclinic crystal systemWurtzite crystal structurePhysical Review B

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High-Pressure High-Temperature Stability and Thermal Equation of State of Zircon-Type Erbium Vanadate.

2018

Inorganic chemistry 57(21), 14005 - 14012 (2018). doi:10.1021/acs.inorgchem.8b01808

DiffractionDYNAMICSEquation of statePhase boundaryThermodynamics02 engineering and technologyzircon010402 general chemistry01 natural sciencesThermal expansionInorganic Chemistrychemistry.chemical_compoundX-RAY-DIFFRACTIONPhase (matter)Physical and Theoretical ChemistryChemistryX-RAY-DIFFRACTION; DYNAMICS021001 nanoscience & nanotechnology5400104 chemical scienceshigh pressureScheeliteX-ray crystallographyddc:5400210 nano-technologyZirconInorganic chemistry

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Structure Solution of the High-Pressure Phase of CuWO4 and Evolution of the Jahn–Teller Distortion

2011

In this work, we have investigated the structural behavior of cuproscheelite up to 33.9 GPa by means of high-pressure single-crystal X-ray diffraction (SXRD) and extended X-ray absorption fine structure (EXAFS). According to EXAFS, beyond 9 GPa a phase transition takes place. On the basis of SXRD, the transition is from the triclinic (P1) structure to a monoclinic (P2/c) structure isotypic to wolframite. The transition implies abrupt changes of CuO6 and WO6 octahedra, but no coordination change. Further, we report the role played by the Jahn–Teller distortion of the CuO6 octahedra on the mechanism of the phase transition as well as the changes in the behavior of the Cu–O bonds for the tricl…

Phase transitionCrystallographyOctahedronExtended X-ray absorption fine structureChemistryGeneral Chemical EngineeringJahn–Teller effectPhase (matter)X-ray crystallographyMaterials ChemistryGeneral ChemistryTriclinic crystal systemMonoclinic crystal systemChemistry of Materials

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CSD 1852498: Experimental Crystal Structure Determination

2018

Related Article: Javier Ruiz-Fuertes, Domingo Martínez-García, Tomás Marqueño, Daniel Errandonea, Simon G. MacLeod, Thomas Bernert, Eiken Haussühl, David Santamaría-Pérez, Jordi Ibáñez, Anitha Mallavarapu, S. Nagabhusan Achary, Catalin Popescu, and Marco Bettinelli|2018|Inorg.Chem.|57|14005|doi:10.1021/acs.inorgchem.8b01808