Prof.
Juras Banys
(Vilnius University)
17/09/2015, 14:20
DyProSo2015 Main track
Talk
The technique of dielectric spectroscopy which overlaps frequency range from 1 mHz to 5 THz is a powerful tool to investigate disordered materials. Such experiments can be combined with FTIR measurements in order to describe the dynamics of polar nanoregions and optical phonons in materials like relaxor ferroelectrics.
In this contribution the broadband dielectric spectroscopy was employed...
Prof.
Andrei Pimenov
(Vienna University of Technology)
17/09/2015, 11:10
DyProSo2015 Main track
Invited Talk
Multiferroics are materials which exhibit electric and magnetic order simultaneously. Due to the coupling of electric and magnetic effects, these materials show a strong potential to control electricity and magnetism and, more generally, the properties and propagation of light. One of the most fascinating and counter-intuitive recent results in multiferroics is directional anisotropy, the...
Petr Ondrejkovic
(Institute of Physics ASCR)
17/09/2015, 13:55
DyProSo2015 Main track
Talk
One of the most remarkable properties of relaxor materials is their extraordinarily large dielectric permittivity appearing over a broad temperature interval and attaining its maximum at a temperature Tmax, which varies linearly with the logarithm of the probing frequency. This frequency-dependent Tmax is described by the Vogel-Fulcher (VF) law and originates from a temperature-dependent...
Dr
Massimiliano Stengel
(ICMAB-CSIC)
14/09/2015, 13:30
DyProSo2015 Main track
Invited Talk
Flexoelectricity describes the electric polarization that is linearly induced by a strain gradient, and is being intensely investigated as a tantalizing new route to converting mechanical stimulation into electrical signals and vice versa. While several breakthrough experiments have been reported in the past few years, progress on the theoretical front has been comparatively slow. The main...
Mr
Fabian Ziegler
(Georg-August-Universität Göttingen), Dr
Holger Gibhardt
(Georg-August-Universität Göttingen)
14/09/2015, 14:10
DyProSo2015 Main track
Talk
Multiferroic materials with magnetic and electric ordering within a single phase gained attention during the last years due to their potential for industrial applications. Materials with a cycloidal spin arrangement are of particular interest because the electrical polarisation is directly caused by the complex magnetic order. Hence, both ordering phenomena are tightly coupled in this category...
Dr
Sophie DE BRION
(Institut Néel)
14/09/2015, 14:35
DyProSo2015 Main track
Talk
Broadband THz spectroscopy is a very useful tool to study complex magnetic/electric order in condensed matter i.e. in multiferroic compounds since both magnetic (magnons) and electric (optical phonons) excitations lie in this energy range. When cross coupling between magnetic and electric order occurs, new kind of excitations may emerge: these are called electro-magnons.
Coupling two...
Prof.
Alois Loidl
(University of Augsburg)
14/09/2015, 11:50
DyProSo2015 Main track
Talk
The lacunar spinel GaV4S8 undergoes orbital ordering at 44 K and reveals a complex magnetic phase diagram below 13 K, including a ferromagnetic, cycloidal and Néel-type skyrmion lattice phase.[1] Skyrmions are topologically protected nano-scale spin vortices with fascinating physical properties and high potential for future data storage. Based on magnetic susceptibility, heat capacity and...
Prof.
Clemens Ulrich
(University of New South Wales)
17/09/2015, 13:30
DyProSo2015 Main track
Talk
Multiferroic materials demonstrate excellent potential for next-generation multifunctional devices, as they exhibit coexisting ferroelectric and magnetic orders. At present, the underlying physics of the magnetoelectric coupling is not fully understood, and competing theories exist with partly conflicting predictions. Therefore, we have investigated isotopically substituted TbMn16/18O3,...
Prof.
István Kézsmárki
(Department of Physics, Budapest University of Technology and Economics)
14/09/2015, 11:10
DyProSo2015 Main track
Invited Talk
Following the early prediction of the skyrmion lattice (SkL)―a periodic array of spin vortices―by Bogdanov and coworkers [1], it has been observed recently in various magnetic crystals mostly with chiral structure [2]. Although non-chiral but polar crystals with Cnv symmetry were identified as ideal SkL hosts in pioneering theoretical studies, this archetype of SkL has remained experimentally...
Mr
Rui Vilarinho Silva
(IFIMUP-IN, Faculty of Sciences, University of Porto, Portugal)
14/09/2015, 15:30
DyProSo2015 Main track
Talk
Multiferroics, where spontaneous long-range magnetic and polar orderings coexist, represent an attractive class of compounds combining rich physics with potential for multifunctional applications. TbMnO3 and DyMnO3 are multiferroics compounds exhibiting magnetic ordering of Mn3+ ions, with a sinusoidal modulated collinear structure below TN = 41K and 39K, and a cycloidal one below Tlock = 27K...
Dr
Stanislav Kamba
(Institute of Physics, The Czech Academy of Sciences, Prague)
17/09/2015, 09:35
DyProSo2015 Main track
Invited Talk
In proper ferroelectrics, the large dielectric anomaly observed at Curie temperature TC is caused by softening of some polar excitation. In displacive ferroelectrics, this excitation is a polar phonon active in far-infrared spectra. In order-disorder ferroelectrics, dielectric relaxation with frequency in the MHz-GHz region drives the ferroelectric phase transition. Many ferroelectrics exhibit...
Dr
Urszula D. Wdowik
(Institute of Technology, Pedagogical University, Podchorazych 2, PL-30084 Cracow, Poland)
17/09/2015, 10:15
DyProSo2015 Main track
Talk
Germanium telluride (GeTe) has attracted an intense renewed interest in the past few years for its relevance and high performance as a phase-change material as such and in combination of the form (GeTe)m(Sb2Te3)n which find useful applications in modern non-volatile data storage devices. Apart from this technological interest, there is a very fundamental issue regarding whether the...
Prof.
Annette Bussmann-Holder
(Max-Planck-Institute for Solid State Research)
17/09/2015, 11:50
DyProSo2015 Main track
Talk
Multiferroic materials with combined polar, magnetic, and elastic orderings are at the forefront of scientific research in view of their multiple interactive couplings. Even though the phenomenon of multiferroicity has been predicted long ago [1], its realization remains rare since polar order is achieved when a transition metal d0 configuration is combined with highly polarizable anions,...
