Güthoff, Friedrich

[["dc.bibliographiccitation.firstpage","11521"],["dc.bibliographiccitation.issue","50"],["dc.bibliographiccitation.journal","Journal of Physics Condensed Matter"],["dc.bibliographiccitation.lastpage","11530"],["dc.bibliographiccitation.volume","13"],["dc.contributor.author","Caspary, D."],["dc.contributor.author","Eckold, Goetz"],["dc.contributor.author","Guthoff, F."],["dc.contributor.author","Pyckhout-Hintzen, W."],["dc.date.accessioned","2018-11-07T11:19:07Z"],["dc.date.available","2018-11-07T11:19:07Z"],["dc.date.issued","2001"],["dc.description.abstract","The kinetic of decomposition in the quasi-binary ionic system AgCl-NaCl has been studied by means of time-resolved neutron diffraction and small-angle neutron scattering. The coherent critical point is estimated as 447 +/- 3 K, 24 K below the upper critical binodal temperature. The chemical decomposition is almost completed in the first 200 s irrespective of the temperature. The mechanical relaxation of the lattice, however, takes place on a much longer timescale and is dominated by coherency strains leading to metastable intermediate states."],["dc.identifier.doi","10.1088/0953-8984/13/50/311"],["dc.identifier.isi","000173436600015"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/55194"],["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","Kinetics of decomposition in ionic solids: II. Neutron scattering study of the system AgCl-NaCl"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.peerReviewed","yes"],["dc.type.status","published"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.artnumber","PII S0953-8984(03)63779-3"],["dc.bibliographiccitation.firstpage","6415"],["dc.bibliographiccitation.issue","37"],["dc.bibliographiccitation.journal","Journal of Physics Condensed Matter"],["dc.bibliographiccitation.lastpage","6426"],["dc.bibliographiccitation.volume","15"],["dc.contributor.author","Caspary, D."],["dc.contributor.author","Eckold, Goetz"],["dc.contributor.author","Elter, P."],["dc.contributor.author","Gibhardt, Holger"],["dc.contributor.author","Guthoff, F."],["dc.contributor.author","Demmel, F."],["dc.contributor.author","Hoser, A."],["dc.contributor.author","Schmidt, W."],["dc.contributor.author","Schweika, W."],["dc.date.accessioned","2018-11-07T10:36:04Z"],["dc.date.available","2018-11-07T10:36:04Z"],["dc.date.issued","2003"],["dc.description.abstract","The dynamics of mixed single crystals of AgxNa1-xCl has been investigated by inelastic neutron scattering before and after chemical demixing. In the homogeneous phase, the concentration dependence of acoustic phonons reveals that doping of NaCl with silver chloride leads to a considerable softening of the lattice, while the elastic properties of AgCl are almost independent of sodium chloride additives. After quenching into the miscibility gap, the phase separation is associated with a well-defined splitting of acoustic phonons which provide the most direct information about the underlying mechanism. In contrast to the local dynamical properties, the lattice structure is essentially determined by coherency strains which hinder the relaxation of lattice parameters. Thus diffraction and inelastic scattering yield independent and complementary information about demixing processes in ionic solids."],["dc.identifier.doi","10.1088/0953-8984/15/37/009"],["dc.identifier.isi","000185909800017"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/45239"],["dc.notes.status","zu prüfen"],["dc.notes.submitter","Najko"],["dc.publisher","Iop Publishing Ltd"],["dc.relation.issn","0953-8984"],["dc.title","The influence of demixing on the dynamics of ionic solids: inelastic neutron scattering from Ag(x)Na(1-x)C1 single crystals"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.peerReviewed","yes"],["dc.type.status","published"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.firstpage","S1169"],["dc.bibliographiccitation.journal","Applied Physics A"],["dc.bibliographiccitation.lastpage","S1171"],["dc.bibliographiccitation.volume","74"],["dc.contributor.author","Elter, P."],["dc.contributor.author","Eckold, Goetz"],["dc.contributor.author","Caspary, D."],["dc.contributor.author","Guthoff, F."],["dc.contributor.author","Hoser, A."],["dc.date.accessioned","2018-11-07T09:43:07Z"],["dc.date.available","2018-11-07T09:43:07Z"],["dc.date.issued","2002"],["dc.description.abstract","Real-time inelastic neutron scattering has been used to characterise the mechanism of decomposition in AgxNa1-xBr mixed single crystals well below the critical temperature on a microscopic scale. The chemical demixing process is associated with a splitting of acoustic phonon branches, which is observed to take place within some 100 s. Interestingly, the Bragg reflections exhibit a completely different time behaviour: the adaptation of the equilibrium lattice parameters occurs on a much longer time scale. Hence, decomposition is governed by large coherency strains which persist over a long period of time. Only in a second stage does the crystal lattice relax into the final equilibrium state."],["dc.identifier.doi","10.1007/s003390201553"],["dc.identifier.isi","000181219600079"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/34104"],["dc.notes.status","zu prüfen"],["dc.notes.submitter","Najko"],["dc.publisher","Springer"],["dc.publisher.place","New york"],["dc.relation.conference","International Conference on Neutron Scattering"],["dc.relation.eventlocation","MUNICH, GERMANY"],["dc.relation.issn","0947-8396"],["dc.title","Time-evolution of phonon spectra during decomposition in AgxNa1-xBr ionic crystals"],["dc.type","conference_paper"],["dc.type.internalPublication","yes"],["dc.type.peerReviewed","yes"],["dc.type.status","published"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.firstpage","83"],["dc.bibliographiccitation.issue","1-3"],["dc.bibliographiccitation.journal","Physica B Condensed Matter"],["dc.bibliographiccitation.lastpage","86"],["dc.bibliographiccitation.volume","350"],["dc.contributor.author","Eckold, Goetz"],["dc.contributor.author","Caspary, D."],["dc.contributor.author","Elter, P."],["dc.contributor.author","Guthoff, F."],["dc.contributor.author","Hoser, A."],["dc.contributor.author","Schmidt, W."],["dc.date.accessioned","2018-11-07T10:47:19Z"],["dc.date.available","2018-11-07T10:47:19Z"],["dc.date.issued","2004"],["dc.description.abstract","Time-resolved inelastic neutron scattering from acoustic phonons has been used to characterise the mechanism of demixing in ionic crystals of the silver alkali halide type. Stroboscopic techniques allow to study the time-evolution of phonon spectra during the phase separation in AgBr-NaBr and AgCl-NaCl single crystals on a time scale of seconds. These data provide the most direct information about changes of interatomic interactions. Characteristic differences are observed for ageing temperatures above and below the spinodal temperature which allow to distinguish between different mechanisms based on nucleation on the one hand and concentration fluctuations on the other. (C) 2004 Elsevier B.V. All rights reserved."],["dc.identifier.doi","10.1016/j.physb.2004.04.058"],["dc.identifier.isi","000223285700021"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/47937"],["dc.notes.status","zu prüfen"],["dc.notes.submitter","Najko"],["dc.publisher","Elsevier Science Bv"],["dc.publisher.place","Amsterdam"],["dc.relation.conference","3rd European Conference on Neutron Scattering (ECNS 2003)"],["dc.relation.eventlocation","Montpellier, FRANCE"],["dc.relation.issn","0921-4526"],["dc.title","Time-resolved phonons as a microscopic probe for demixing processes"],["dc.type","conference_paper"],["dc.type.internalPublication","yes"],["dc.type.peerReviewed","yes"],["dc.type.status","published"],["dspace.entity.type","Publication"]]