921 citations · 3.9k across the 63 of their papers we have counts for
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Antipolar transitions in GaNbSe and GaTaSe
M. Winkler, L. Prodan, V. Tsurkan +2
We present dielectric, polarization, resistivity, specific heat, and magnetic susceptibility data on single crystals of the lacunar spinels GaNb4Se8 and GaTa4Se8, tetrahedral clust…
Optical, dielectric, and magnetoelectric properties of ferroelectric and antiferroelectric lacunar spinels
K. Geirhos, S. Reschke, S. Ghara +3
Lacunar spinels with a chemical formula of form a populous family of narrow-gap semiconductors, which offer a fertile ground to explore correlation and quantum phenomena,…
Spin liquid and ferroelectricity close to a quantum critical point in PbCuTeO
Christian Thurn, Paul Eibisch, Arif Ata +13
Geometrical frustration among interacting spins combined with strong quantum fluctuations destabilize long-range magnetic order in favour of more exotic states such as spin liquids…
Intriguing relaxor ferroelectricity in a polar CT crystal at the neutral-ionic interface
J. K. H. Fischer, G. D'Avino, M. Masino +4
We investigated the mixed-stack charge-transfer crystal, N,N'-dimethylphenazine-TCNQ (MP-TCNQ), which is polar at room temperature and just at the neutral-to-ionic interface (i…
Cooperative cluster-Jahn-Teller effect as a possible route to antiferroelectricity
K. Geirhos, J. Langmann, L. Prodan +8
We report the observation of an antipolar phase in cubic GaNbS driven by an unconventional microscopic mechanism, the cooperative Jahn-Teller effect of NbS molecula…
Macroscopic Manifestation of Domain-wall Magnetism and Magnetoelectric Effect in a Néel-type Skyrmion Host
K. Geirhos, B. Gross, B. G. Szigeti +12
We report a magnetic state in GaVSe which emerges exclusively in samples with mesoscale polar domains and not in polar mono-domain crystals. Its onset is accompanied with a…
Chirality-driven ferroelectricity in LiCuVO
Alexander Ruff, Peter Lunkenheimer, Hans-Albrecht Krug von Nidda +5
Chirality or the handedness of objects is of prime importance in life science, biology, chemistry and physics. It is also a major symmetry ingredient in frustrated magnets revealin…
Multiferroic spin-superfluid and spin-supersolid phases in MnCr2S4
Alexander Ruff, Zhaosheng Wang, Sergei Zherlitsyn +6
Spin supersolids and spin superfluids reveal complex canted spin structures with independent order of longitudinal and transverse spin components. This work addresses the question…
Relaxation dynamics in the one-dimensional organic charge-transfer salt δ-(EDT-TTF-CONMe)Br
J. K. H. Fischer, P. Lunkenheimer, C. Leva +6
A detailed investigation of the charge-ordered charge-transfer salt δ-(EDT-TTF-CONMe)Br by thermal-expansion measurements and dielectric spectroscopy reveals three dyna…
Evidence for electronically-driven ferroelectricity in the family of strongly correlated dimerized BEDT-TTF molecular conductors
Elena Gati, Jonas K. H. Fischer, Peter Lunkenheimer +10
By applying measurements of the dielectric constants and relative length changes to the dimerized molecular conductor -(BEDT-TTF)Hg(SCN)Cl, we provide evidence for order…
Excitations and relaxation dynamics in multiferroic GeV4S8 studied by THz and dielectric spectroscopy
S. Reschke, Zhe Wang, F. Mayr +4
We report on THz time-domain spectroscopy on multiferroic GeV4S8, which undergoes orbital ordering at a Jahn-Teller transition at 30.5 K and exhibits antiferromagnetic order below…
Polar and magnetic order in GaV4Se8
E. Ruff, A. Butykai, K. Geirhos +6
In the present work, we provide results from specific heat, magnetic susceptibility, dielectric constant, ac conductivity, and electrical polarization measurements performed on the…
Structural, magnetic, electric, dielectric, and thermodynamic properties of multiferroic GeV4S8
S. Widmann, A. Günther, E. Ruff +4
The lacunar spinel GeV4S8 undergoes orbital and ferroelectric ordering at the Jahn-Teller transition around 30 K and exhibits antiferromagnetic order below about 14 K. In addition…
On the multiferroic skyrmion-host GaV4S8
S. Widmann, E. Ruff, A. Günther +6
The lacunar spinel GaV4S8 exhibits orbital ordering at 44 K and shows a complex magnetic phase diagram below 12.7 K, which includes ferromagnetic and cycloidal spin order. At low b…
Polar Dynamics at the Jahn-Teller Transition in Ferroelectric GaV4S8
Zhe Wang, E. Ruff, M. Schmidt +4
We present a dielectric spectroscopy study of the polar dynamics linked to the orbitally driven ferroelectric transition in the skyrmion host GaV4S8. By combining THz and MHz-GHz s…
Multiferroicity and skyrmions carrying electric polarization in GaV4S8
E. Ruff, S. Widmann, P. Lunkenheimer +4
Skyrmions are whirl like topological spin objects with high potential for future magnetic data storage. It is a fundamental question, relevant for both basic research and applicati…
Spin-orbiton and quantum criticality in FeSc2S4
L. Mittelstädt, M. Schmidt, Zhe Wang +7
In FeSc2S4 spin-orbital exchange competes with strong spin-orbit coupling, suppressing long-range spin and orbital order and, hence, this material represents one of the rare exampl…
Multiferroicity in the Mott Insulating Charge-Transfer Salt κ-(BEDT-TTF)Cu[N(CN)]Cl
M. Lang, P. Lunkenheimer, J. Müller +6
The recently proposed multiferroic state of the charge-transfer salt κ-(BEDT-TTF)Cu[N(CN)]Cl [P. Lunkenheimer et al., Nature Mater., vol. 11, pp. 755-758, Sept. 2012] has b…
Multiferroicity in an organic charge-transfer salt: Electric-dipole-driven magnetism
P. Lunkenheimer, J. Müller, S. Krohns +8
Multiferroics, showing simultaneous ordering of electrical and magnetic degrees of freedom, are remarkable materials as seen from both the academic and technological points of view…
Magnetic susceptibility, phonons and dielectric constant of single crystalline BiFeO3
Jun Lu, M Schmidt, P Lunkenheimer +4
The magnetic susceptibility between 1.5 and 800 K, the infrared reflectivity at room temperature and the temperature dependence of the dielectric constant at mm-wavelengths are rep…
Optical Spectroscopy in CoO: Phonons, Electric, and Magnetic Excitations
Ch. Kant, T. Rudolf, F. Schrettle +5
The reflectivity of single-crystalline CoO has been studied by optical spectroscopy for wave numbers ranging from 100 to 28,000\wn and for temperatures 8 325 K\@. A splitti…
Switching the Ferroelectric Polarization by External Magnetic Fields in the Spin = 1/2 Chain Cuprate LiCuVO4
F. Schrettle, S. Krohns, P. Lunkenheimer +5
We present a detailed study of complex dielectric constant and ferroelectric polarization in multiferroic LiCuVO4 as function of temperature and external magnetic field. In zero ex…
Broadband dielectric response of CaCu3Ti4O12: From dc to the electronic transition regime
Ch. Kant, T. Rudolf, F. Mayr +4
We report on phonon properties and electronic transitions in CaCu3Ti4O12, a material which reveals a colossal dielectric constant at room temperature without any ferroelectric tran…
Multiferroicity and colossal magneto-capacitance in Cr-thiospinels
J. Hemberger, P. Lunkenheimer, R. Fichtl +3
The sulfur based Cr-spinels RCr2S4 with R = Cd and Hg exhibit the coexistence of ferromagnetic and ferroelectric properties together with a pronounced magnetocapacitive coupling. W…