0000000001311561

AUTHOR

M. Rok

showing 5 related works from this author

A multiaxial electrical switching in a one-dimensional organic–inorganic (pyrrolidinium)2Cd2I6ferroelectric and photoluminescent crystal

2021

Ferroelectric materials exhibiting more than one polar phase are very attractive in terms of application. The advantage of such materials is temperature-dependent switching between two different ferroelectric states. Here we report on the discovery of a unique, continuous ferroelectric – ferroelectric transformation in (C4H10N)2[Cd2I6], PCdI at 220 K. Thermal measurements suggest that phase transition is close to the continuous one. Both phases belong to the same polar monoclinic Cc space group. Temperature-variable X-ray diffraction measurements of single crystals confirm the polar nature of the two phases (I and II). The anionic network is in the form of [Cd2I6]2− 1D chains, with pyrrolid…

Materials sciencePhotoluminescence02 engineering and technologyGeneral ChemistryDielectric010402 general chemistry021001 nanoscience & nanotechnology01 natural sciencesFerroelectricity0104 chemical sciencesPyroelectricityCrystalCondensed Matter::Materials ScienceCrystallographyPhase (matter)Materials ChemistryPhotoluminescence excitation0210 nano-technologyMonoclinic crystal systemJournal of Materials Chemistry C
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Isostructural phase transition, quasielastic neutron scattering and magnetic resonance studies of a bistable dielectric ion-pair crystal [(CH3)2NH2]2…

2019

We have synthesised and characterised a novel organic–inorganic hybrid crystal, [(CH3)2NH2]2KCr(CN)6. The thermal DSC, TMA, DTG and DTA analyses indicate two solid-to-solid structural phase transitions (PTs). According to the X-ray diffraction experiments, the first PT at 220 K is isostructural, since it does not involve a change of the space group. This transition occurs between the states, where the (CH3)2NH2+ cations are orientationally disordered and ordered (frozen). The other reversible PT at 481 K leads to a melt-like phase similar to the one observed in plastic crystals or polar liquids. Dielectric spectroscopy has been used to characterise the switching properties of the dipole mom…

Phase transitionMaterials science010405 organic chemistryDielectric010402 general chemistry01 natural sciences0104 chemical sciencesIonDielectric spectroscopyInorganic ChemistryDipoleCrystallographyQuasielastic neutron scatteringPlastic crystalIsostructuralDalton Transactions
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Cyano-bridged perovskite [(CH3)3NOH]2[KM(CN)6],[M: Fe(III), Co(III)] for high-temperature multi-axial ferroelectric applications with enhanced therma…

2020

Highly stable ferroelectrics with reversible high-temperature phase transitions and switchable nonlinear optical behaviour are much coveted targets for emerging optoelectronic applications. Here, we demonstrate a cyano-bridged perovskite [(CH3)3NOH]2[KCo(CN)6] (TMAO-Co), a new analogue of the multi-axial ferroelectric [(CH3)3NOH]2[KFe(CN)6] (TMAO-Fe) with improved thermal stability and enhanced second-order nonlinear optical response. Indeed, for TMAO-Co the Curie temperature (Tc) is shifted to a higher value of ca. 416 K (improvement by ca. 10 K versusTMAO-Fe); the separation between Tc and the decomposition threshold is 46 K. TMAO-Co is a biaxial ferroelectric as revealed by P(E) hysteres…

Phase transitionMaterials scienceInfraredGeneral ChemistryMolecular physicsFerroelectricitysymbols.namesakeMaterials ChemistrysymbolsCurie temperatureThermal stabilityRaman spectroscopyPerovskite (structure)Monoclinic crystal systemJournal of Materials Chemistry C
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CCDC 1879412: Experimental Crystal Structure Determination

2019

Related Article: M. Rok, G. Bator, B. Zarychta, B. Dziuk, J. Repeć, W. Medycki, M. Zamponi, G. Usevičius, M. Šimėnas, J. Banys|2019|Dalton Trans.|48|4190|doi:10.1039/C8DT05082A

Space GroupCrystallographyCrystal SystemCrystal StructureCell Parameterscatena-(bis(dimethylammonium) hexakis(mu-cyano)-chromium-potassium)Experimental 3D Coordinates
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CCDC 1879413: Experimental Crystal Structure Determination

2019

Related Article: M. Rok, G. Bator, B. Zarychta, B. Dziuk, J. Repeć, W. Medycki, M. Zamponi, G. Usevičius, M. Šimėnas, J. Banys|2019|Dalton Trans.|48|4190|doi:10.1039/C8DT05082A

Space GroupCrystallographyCrystal SystemCrystal StructureCell Parameterscatena-(bis(dimethylammonium) hexakis(mu-cyano)-chromium-potassium)Experimental 3D Coordinates
researchProduct