@article{RamanVenkatesanSmykallaPlossetal.2022, author = {Raman Venkatesan, Thulasinath and Smykalla, David and Ploss, Bernd and W{\"u}bbenhorst, Michael and Gerhard, Reimund}, title = {Tuning the relaxor-ferroelectric properties of Poly(vinylidene fluoride-trifluoroethylene-chlorofluoroethylene) Terpolymer films by means of thermally induced micro- and nanostructures}, series = {Macromolecules : a publication of the American Chemical Society}, volume = {55}, journal = {Macromolecules : a publication of the American Chemical Society}, number = {13}, publisher = {American Chemical Society}, address = {Washington}, issn = {0024-9297}, doi = {10.1021/acs.macromol.2c00302}, pages = {5621 -- 5635}, year = {2022}, abstract = {The effects of thermal processing on the micro- and nanostructural features and thus also on the relaxor-ferroelectric properties of a P(VDF-TrFE-CFE) terpolymer were investigated in detail by means of dielectric experiments, such as dielectric relaxation spectroscopy (DRS), dielectric hysteresis loops, and thermally stimulated depolarization currents (TSDCs). The results were correlated with those obtained from differential scanning calorimetry (DSC), wide-angle X-ray diffraction (WAXD), and Fourier-transform infrared spectroscopy (FTIR). The results from DRS and DSC show that annealing reduces the Curie transition temperature of the terpolymer, whereas the results from WAXD scans and FTIR spectra help to understand the shift in the Curie transition temperatures as a result of reducing the ferroelectric phase fraction, which by default exists even in terpolymers with relatively high CFE contents. In addition, the TSDC traces reveal that annealing has a similar effect on the midtemperature transition by altering the fraction of constrained amorphous phase at the interphase between the crystalline and the amorphous regions. Changes in the transition temperatures are in turn related to the behavior of the hysteresis curves on differently heat-treated samples. During heating, evolution of the hysteresis curves from ferroelectric to relaxor-ferroelectric, first exhibiting single hysteresis loops and then double hysteresis loops near the Curie transition of the sample, is observed. When comparing the dielectric-hysteresis loops obtained at various temperatures, we find that annealed terpolymer films show higher electric-displacement values and lower coercive fields than the nonannealed sample, irrespective of the measurement temperature, and also exhibit ideal relaxor- ferroelectric behavior at ambient temperatures, which makes them excellent candidates for applications at or near room temperature. By tailoring the annealing conditions, it has been shown that the application temperature could be increased by fine tuning the induced micro- and nanostructures.}, language = {en} } @article{BeyeWernetSchuesslerLangeheineetal.2013, author = {Beye, Martin and Wernet, Ph. and Sch{\"u}ßler-Langeheine, Christian and F{\"o}hlisch, Alexander}, title = {Time resolved resonant inelastic X-ray scattering: a supreme tool to understand dynamics in solids and molecules}, series = {Journal of electron spectroscopy and related phenomena : the international journal on theoretical and experimental aspects of electron spectroscopy}, volume = {188}, journal = {Journal of electron spectroscopy and related phenomena : the international journal on theoretical and experimental aspects of electron spectroscopy}, number = {3}, publisher = {Elsevier}, address = {Amsterdam}, issn = {0368-2048}, doi = {10.1016/j.elspec.2013.04.013}, pages = {172 -- 182}, year = {2013}, abstract = {Dynamics in materials typically involve different degrees of freedom, like charge, lattice, orbital and spin in a complex interplay. Time-resolved resonant inelastic X-ray scattering (RIXS) as a highly selective tool can provide unique insight and follow the details of dynamical processes while resolving symmetries, chemical and charge states, momenta, spin configurations, etc. In this paper, we review examples where the intrinsic scattering duration time is used to study femtosecond phenomena. Free-electron lasers access timescales starting in the sub-ps range through pump-probe methods and synchrotrons study the time scales longer than tens of ps. In these examples, time-resolved resonant inelastic X-ray scattering is applied to solids as well as molecular systems.}, language = {en} }