Eckold, Götz

[["dc.bibliographiccitation.artnumber","015005"],["dc.bibliographiccitation.issue","1"],["dc.bibliographiccitation.journal","Materials Research Express"],["dc.bibliographiccitation.volume","2"],["dc.contributor.author","Gibhardt, Holger"],["dc.contributor.author","Leist, Jeannis"],["dc.contributor.author","Eckold, Goetz"],["dc.date.accessioned","2018-11-07T10:02:31Z"],["dc.date.available","2018-11-07T10:02:31Z"],["dc.date.issued","2015"],["dc.description.abstract","The domain structure of SrTiO3 below its cubic to tetragonal phase transition depends not only on the stress-state of a particular sample but can also be modified very efficiently by the application of electric fields. Hence, the interpretation of field induced phenomena needs a careful consideration of the domain distribution which is often neglected in existing studies. In this paper, it is shown that the strong variation of polarized Raman spectra under external fields observed within both the para-electric tetragonal phase and the field induced ferroelectric phase, is a direct consequence of the redistribution of domains. Raman data can therefore be used to characterize the domain structure of a particular sample."],["dc.identifier.doi","10.1088/2053-1591/2/1/015005"],["dc.identifier.isi","000369978500005"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/38244"],["dc.notes.status","zu prüfen"],["dc.notes.submitter","Najko"],["dc.publisher","Iop Publishing Ltd"],["dc.relation.issn","2053-1591"],["dc.title","Influence of electric field and domain structure on the low-temperature Raman spectra of SrTiO3"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.peerReviewed","yes"],["dc.type.status","published"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.artnumber","415209"],["dc.bibliographiccitation.issue","41"],["dc.bibliographiccitation.journal","Journal of Physics Condensed Matter"],["dc.bibliographiccitation.volume","20"],["dc.contributor.author","Leist, Jeannis"],["dc.contributor.author","Gibhardt, Holger"],["dc.contributor.author","Hradil, Klaudia"],["dc.contributor.author","Eckold, Goetz"],["dc.date.accessioned","2018-11-07T11:10:02Z"],["dc.date.available","2018-11-07T11:10:02Z"],["dc.date.issued","2008"],["dc.description.abstract","The lock-in transition of K2SeO4 at 93.2 K was studied using high-resolution. gamma-ray diffraction, in situ dielectric measurements and neutron scattering. The phase transition shows a coexistence regime of 1.0 K with clearly resolved incommensurate and commensurate satellite reflections. Within a temperature interval of several K above the lock-in transition, strong third order satellites are observed, indicating a pronounced squaring of the modulation wave. Under the influence of high electric fields an intermediate phase is observed, which is characterized by a diffuse intensity distribution. In addition, the dielectric permittivity exhibits two maxima, indicating the existence of two separate phase transitions. This behaviour is attributed to distortions of the discommensuration lattice and pinning of the discommensurations by accumulated charged defects. It seems to be characteristic for modulated ferroelectrics of the A(2)BX(4) group, since a similar behaviour is also found in isostructural Rb2ZnCl4 and K2ZnCl4. The soft-mode dynamics close to T-c is found to be essentially independent of the electric field and not affected by the discommensuration lattice."],["dc.description.sponsorship","DFG [EC153/2-2]"],["dc.identifier.doi","10.1088/0953-8984/20/41/415209"],["dc.identifier.isi","000259693500016"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/53129"],["dc.notes.status","zu prüfen"],["dc.notes.submitter","Najko"],["dc.publisher","Iop Publishing Ltd"],["dc.relation.issn","1361-648X"],["dc.relation.issn","0953-8984"],["dc.title","Electric field induced anomalies in ferroelectric K2SeO4"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.peerReviewed","yes"],["dc.type.status","published"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.artnumber","305901"],["dc.bibliographiccitation.issue","30"],["dc.bibliographiccitation.journal","Journal of Physics Condensed Matter"],["dc.bibliographiccitation.volume","23"],["dc.contributor.author","Leist, Jeannis"],["dc.contributor.author","Gibhardt, Holger"],["dc.contributor.author","Hradil, Klaudia"],["dc.contributor.author","Eckold, Goetz"],["dc.date.accessioned","2018-11-07T08:53:22Z"],["dc.date.available","2018-11-07T08:53:22Z"],["dc.date.issued","2011"],["dc.description.abstract","The field induced switching process across the ferroelectric lock-in transition in K2SeO4 has been studied on a millisecond timescale using stroboscopic neutron diffraction. The time evolution of both the first and the third order satellites was examined. The time constants are found to vary with temperature between 0.2 and 1.2 ms. This is an order of magnitude faster than in the isostructural Rb2ZnCl4. Moreover, the time dependence of the satellite's linewidth provides information about the evolution of the coherence of the modulated structure."],["dc.description.sponsorship","DFG [EC153/2-2]"],["dc.identifier.doi","10.1088/0953-8984/23/30/305901"],["dc.identifier.isi","000292930800014"],["dc.identifier.pmid","21753240"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/22387"],["dc.notes.status","zu prüfen"],["dc.notes.submitter","Najko"],["dc.publisher","Iop Publishing Ltd"],["dc.relation.issn","1361-648X"],["dc.relation.issn","0953-8984"],["dc.title","Switching behaviour of modulated ferroelectrics: the kinetics of the field induced lock-in transition in K2SeO4"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.peerReviewed","yes"],["dc.type.status","published"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.artnumber","335901"],["dc.bibliographiccitation.issue","33"],["dc.bibliographiccitation.journal","Journal of Physics Condensed Matter"],["dc.bibliographiccitation.volume","24"],["dc.contributor.author","Dura, L."],["dc.contributor.author","Gibhardt, Holger"],["dc.contributor.author","Leist, Jeannis"],["dc.contributor.author","Becker, P."],["dc.contributor.author","Bohaty, L."],["dc.contributor.author","Eckold, Goetz"],["dc.date.accessioned","2018-11-07T09:07:08Z"],["dc.date.available","2018-11-07T09:07:08Z"],["dc.date.issued","2012"],["dc.description.abstract","Dynamic anomalies have been found in the magnetically ordered phases of multiferroic MnWO4 using polarized Raman scattering. Strong phonon damping is observed for several B-g modes within the ferroelectric phase and has been attributed to spin-phonon interactions. Moreover, a new low frequency excitation was detected near 33 cm(-1) that grows in intensity on cooling into the antiferromagnetic phases. It is argued that this signal is most probably due to a two-magnon process."],["dc.description.sponsorship","DFG [SFB 608]"],["dc.identifier.doi","10.1088/0953-8984/24/33/335901"],["dc.identifier.isi","000306997300016"],["dc.identifier.pmid","22836380"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/25719"],["dc.notes.status","zu prüfen"],["dc.notes.submitter","Najko"],["dc.publisher","Iop Publishing Ltd"],["dc.relation.issn","0953-8984"],["dc.title","Low frequency excitations in multiferroic MnWO4"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.peerReviewed","yes"],["dc.type.status","published"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.artnumber","144406"],["dc.bibliographiccitation.issue","14"],["dc.bibliographiccitation.journal","PHYSICAL REVIEW B"],["dc.bibliographiccitation.volume","89"],["dc.contributor.author","Baum, M."],["dc.contributor.author","Leist, Jeannis"],["dc.contributor.author","Finger, Tobias"],["dc.contributor.author","Schmalzl, K."],["dc.contributor.author","Hiess, Arno"],["dc.contributor.author","Regnault, L. P."],["dc.contributor.author","Becker, P."],["dc.contributor.author","Bohaty, L."],["dc.contributor.author","Eckold, Goetz"],["dc.contributor.author","Braden, M."],["dc.date.accessioned","2018-11-07T09:41:20Z"],["dc.date.available","2018-11-07T09:41:20Z"],["dc.date.issued","2014"],["dc.description.abstract","The time dependence of switching multiferroic domains in MnWO4 has been studied by time-resolved polarized neutron diffraction. Inverting an external electric field inverts the chiral magnetic component within rise times ranging between a few and some tens of milliseconds in perfect agreement with macroscopic techniques. There is no evidence for any faster process in the inversion of the chiral magnetic structure. The time dependence is well described by a temperature-dependent rise time suggesting a well-defined process of domain reversion. As expected, the rise times decrease when heating towards the upper boundary of the ferroelectric phase. However, switching also becomes faster upon cooling towards the lower boundary, which is associated with a first-order phase transition."],["dc.identifier.doi","10.1103/PhysRevB.89.144406"],["dc.identifier.isi","000334115200004"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/33706"],["dc.notes.status","zu prüfen"],["dc.notes.submitter","Najko"],["dc.publisher","Amer Physical Soc"],["dc.relation.issn","2469-9969"],["dc.relation.issn","2469-9950"],["dc.title","Kinetics of the multiferroic switching in MnWO4"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.peerReviewed","yes"],["dc.type.status","published"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.artnumber","465901"],["dc.bibliographiccitation.issue","46"],["dc.bibliographiccitation.journal","Journal of Physics Condensed Matter"],["dc.bibliographiccitation.volume","25"],["dc.contributor.author","Leist, Jeannis"],["dc.contributor.author","Gibhardt, Holger"],["dc.contributor.author","Eckold, Goetz"],["dc.date.accessioned","2018-11-07T09:17:29Z"],["dc.date.available","2018-11-07T09:17:29Z"],["dc.date.issued","2013"],["dc.description.abstract","The kinetics of the ferroelectric lock-in transition in potassium selenate (K2SeO4) was studied on a millisecond timescale using high-resolution gamma-ray diffraction. A large change of the line width and wavevector of the first order satellite is observed during the switching process. This is attributed to a loss of long-range order under the influence of the electric field. In addition, the incommensurate phase is stabilized by the pulsed field and the transition to the pure commensurate phase is shifted to lower temperatures. Strains that may build up during the rapid switching process are supposed to be the reason for this behaviour."],["dc.description.sponsorship","DFG [EC153/2-2]"],["dc.identifier.doi","10.1088/0953-8984/25/46/465901"],["dc.identifier.isi","000326674700022"],["dc.identifier.pmid","24132071"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/28181"],["dc.notes.status","zu prüfen"],["dc.notes.submitter","Najko"],["dc.publisher","Iop Publishing Ltd"],["dc.relation.issn","1361-648X"],["dc.relation.issn","0953-8984"],["dc.title","Switching kinetics of the ferroelectric transition in K2SeO4 studied by stroboscopic gamma-ray diffraction"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.peerReviewed","yes"],["dc.type.status","published"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.artnumber","096103"],["dc.bibliographiccitation.issue","9"],["dc.bibliographiccitation.journal","Materials Research Express"],["dc.bibliographiccitation.volume","2"],["dc.contributor.affiliation","Ziegler, Fabian;"],["dc.contributor.affiliation","Gibhardt, Holger;"],["dc.contributor.affiliation","Leist, Jeannis;"],["dc.contributor.affiliation","Eckold, Götz;"],["dc.contributor.author","Ziegler, Fabian"],["dc.contributor.author","Gibhardt, Holger"],["dc.contributor.author","Leist, Jeannis"],["dc.contributor.author","Eckold, Götz"],["dc.date.accessioned","2018-11-07T09:51:52Z"],["dc.date.available","2018-11-07T09:51:52Z"],["dc.date.issued","2015"],["dc.date.updated","2022-02-09T13:18:41Z"],["dc.description.abstract","MnWO4 passes three antiferromagnetic phase transitions below the Neel temperature T-N = 13.5 K. One of these phases is also ferroelectric and MnWO4 is therefore referred to as multiferroic. We investigated the effect of magnetic and electric ordering on the lattice dynamics by high-resolution polarized Raman spectroscopy. With an accuracy of about 0.02 cm(-1), anomalous shifts of nearly all Raman-active phonon wave numbers were observed below T-N. High-energy metal-oxygen stretching modes soften on cooling, while low-energy vibrations become harder. Due to their linear temperature dependence, these anomalies can be attributed to a higher-order spin-phonon coupling process. The phonon line widths are unaffected by the magnetic phase transitions and continuously increase with temperature as expected for three-phonon decay processes."],["dc.identifier.doi","10.1088/2053-1591/2/9/096103"],["dc.identifier.eissn","2053-1591"],["dc.identifier.isi","000370057200044"],["dc.identifier.purl","https://resolver.sub.uni-goettingen.de/purl?gs-1/13120"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/35999"],["dc.language.iso","en"],["dc.notes.status","zu prüfen"],["dc.notes.submitter","Najko"],["dc.publisher","IOP Publishing"],["dc.relation.issn","2053-1591"],["dc.rights.access","openAccess"],["dc.rights.uri","http://creativecommons.org/licenses/by/3.0/"],["dc.title","High-resolution polarised Raman scattering study on spin-phonon coupling in multiferroic MnWO4"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.peerReviewed","yes"],["dc.type.status","published"],["dc.type.version","published_version"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.firstpage","200"],["dc.bibliographiccitation.issue","1"],["dc.bibliographiccitation.journal","Ferroelectrics"],["dc.bibliographiccitation.lastpage","209"],["dc.bibliographiccitation.volume","505"],["dc.contributor.author","Sidoruk, Jakob"],["dc.contributor.author","Leist, Jeannis"],["dc.contributor.author","Gibhardt, Holger"],["dc.contributor.author","Sobolev, Oleg"],["dc.contributor.author","Ouladdiaf, Bachir"],["dc.contributor.author","Mole, Richard"],["dc.contributor.author","Eckold, Goetz"],["dc.date.accessioned","2018-11-07T10:19:37Z"],["dc.date.available","2018-11-07T10:19:37Z"],["dc.date.issued","2016"],["dc.description.abstract","SrTiO3 is a well-studied perovskite system which undergoes an antiferrodistortive phase transition at 105K. The low-temperature tetragonal phase exhibits different domains corresponding to the orientation of the symmetry axis. The domain structure can be changed drastically by applying electric fields. Using time-resolved neutron diffraction, the kinetics of the domain redistribution has been investigated on a time scale between microseconds and seconds. It is shown that there are at least two different types of relaxation processes on different time scales which govern the transformation. These can be related to the motion of hard and easy domain walls. Moreover, it is demonstrated that at low temperatures the field induced transition into the ferroelectric phase reveals a significant hysteresis which is reflected by the distribution of tetragonal domains. This finding supports the view of the zero field so-called quantum-paraelectric or coherent-paraelectric phase consisting of polar clusters which are removed only by heating above 40K."],["dc.description.sponsorship","DFG [EC-153/4-1]"],["dc.identifier.doi","10.1080/00150193.2016.1258687"],["dc.identifier.isi","000392617400021"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/41702"],["dc.notes.status","zu prüfen"],["dc.notes.submitter","Najko"],["dc.publisher","Taylor & Francis Ltd"],["dc.relation.issn","1563-5112"],["dc.relation.issn","0015-0193"],["dc.title","Kinetics of domain redistribution in SrTiO3 under pulsed electric fields"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.peerReviewed","yes"],["dc.type.status","published"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.artnumber","235903"],["dc.bibliographiccitation.issue","23"],["dc.bibliographiccitation.journal","Journal of Physics Condensed Matter"],["dc.bibliographiccitation.volume","22"],["dc.contributor.author","Sidoruk, Jakob"],["dc.contributor.author","Leist, Jeannis"],["dc.contributor.author","Gibhardt, Holger"],["dc.contributor.author","Meven, M."],["dc.contributor.author","Hradi, K."],["dc.contributor.author","Eckold, Goetz"],["dc.date.accessioned","2018-11-07T08:42:13Z"],["dc.date.available","2018-11-07T08:42:13Z"],["dc.date.issued","2010"],["dc.description.abstract","Below its ordering temperature at 105 K, perovskite-type SrTiO3 exhibits a tetragonal phase with three different structural domains that are strongly influenced by the application of uniaxial mechanical stresses and electric fields. A careful neutron diffraction study of superlattice reflections provides full quantitative information about the varying domain distributions under external loads as a function of temperature. It is shown that electric field and uniaxial stress exhibit competitive effects and the simultaneous application leads to a complex redistribution behaviour of the tetragonal domains. The results are discussed in the context of the formation of a field induced ferroelectric phase at low temperatures. The experimental findings demonstrate that its polarization is always perpendicular to the tetragonal axis and the polar phase has orthorhombic symmetry."],["dc.identifier.doi","10.1088/0953-8984/22/23/235903"],["dc.identifier.isi","000278077600015"],["dc.identifier.pmid","21393772"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/19650"],["dc.notes.status","zu prüfen"],["dc.notes.submitter","Najko"],["dc.publisher","Iop Publishing Ltd"],["dc.relation.issn","0953-8984"],["dc.title","Quantitative determination of domain distribution in SrTiO3-competing effects of applied electric field and mechanical stress"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.peerReviewed","yes"],["dc.type.status","published"],["dspace.entity.type","Publication"]]