Crystal structure and phase transitions of a layered perovskite-like CsScF₄crystal

Abstract

This work is devoted to the complex research on temperature phase transitions in a CsScF 4 crystal. The crystal structure was solved and refined at different temperatures by using the Rietveld method. Structural phase transitions were investigated by using the following spectroscopic methods, some of them for the first time: Brillouin spectroscopy, Raman spectroscopy, IR absorption spectroscopy and NMR. The symmetry analysis of the Brillouin zone center of all phases is presented. The vibrational spectra of the crystal in three phases have been calculated. The structural phase transition mechanism was determined. The transitions at T 1 = 475 K and T 2 = 317.5 K are of displacement type. The Raman soft modes have been associated with rotations of the ScF 6 octahedral group.8472 | CrystEngComm, 2016, 18, 8472-8486This journal is

Structure, Thermal Stability, and Spectroscopic Properties of Triclinic Double Sulfate AgEu(SO4)2 with Isolated SO4 Groups

“…The dependencies F ( r ij ) are the same for all atom pairs: F ( r ij ) = λexp­(− r ij /ρ), where λ and ρ are the parameters characterizing selected pair interaction. To find the parameters of the model, the special optimization program was written and tested for several representative compounds. ,,,− The crystal lattice stability conditions were taken into account. The parameters obtained for AgEu­(SO 4 ) 2 are shown in Table S3.…”

Polymorphs of Rb3ScF6: X-ray and Neutron Diffraction, Solid-State NMR, and Density Functional Theory Calculations Study

“…Structural studies on almost all reported lithium, potassium, and sodium fluoroscandates have been performed. Recently, the structures of two members of the CsF-ScF 3 system, CsScF 4 and CsSc 3 F 10 , have been reported. , However, rubidium-containing fluoride compounds have been overlooked. Only the structure of the RT RbSc 3 F 10 polymorph has been reported to date.…”

Combining solid state NMR, powder X-ray diffraction, and DFT calculations for CsSc3F10 structure determination

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