A5081319948- Organic and Molecular Conductors Research
- Electronic and Structural Properties of Oxides
- Solid-state spectroscopy and crystallography
- Multiferroics and related materials
- Perovskite Materials and Applications
- Magnetic Properties and Synthesis of Ferrites
- Acoustic Wave Resonator Technologies
- Gas Sensing Nanomaterials and Sensors
- Physics of Superconductivity and Magnetism
- Magnetic and transport properties of perovskites and related materials
- 2D Materials and Applications
- Magnetic properties of thin films
- Molecular Junctions and Nanostructures
- Transition Metal Oxide Nanomaterials
- Magnetic Properties and Applications
- Advanced Condensed Matter Physics
- Force Microscopy Techniques and Applications
- Semiconductor materials and devices
- Material Science and Thermodynamics
- Phase-change materials and chalcogenides
- Catalytic Processes in Materials Science
- Marine and environmental studies
- Material Dynamics and Properties
- Iron oxide chemistry and applications
- Fullerene Chemistry and Applications
Institute of Physics
2013-2024
Johannes Gutenberg University Mainz
2018-2019
University of Kentucky
2006-2009
University of Zagreb
2005
We observe the excitation of collective modes in THz range driven by recently discovered N\'{e}el spin-orbit torques (NSOT) metallic antiferromagnet Mn$_{2}$Au. Temperature dependent spectroscopy reveals a strong absorption mode centered near 1 THz, which upon heating from 4 K to 450 softens and looses intensity. Comparison with estimated eigenmode frequencies implies that observed is an in-plane antiferromagnetic resonance (AFMR) mode. The AFMR strength exceeds those found insulators,...
Hierarchical porous carbons are known to enhance the electrochemical features of electrodes in capacitors. However, contribution surface oxygen and resulting functionalities wettability, along with role electrical conductivity degree amorphous or crystalline nature micro-mesoporous carbons, not yet clear. This article considers effect carbonisation temperature (500-900 °C) type activation (CO2, KOH) on properties mentioned above case carbon xerogels (CXs) understand performances. Depending...
The search for new materials energy-efficient electronic devices has gained unprecedented importance. Among the various classes of magnetic driving this are antiferromagnets, magnetoelectrics, and systems with topological spin excitations. Cu_{3}TeO_{6} is a material that belongs to all three these classes. Combining static electric polarization torque measurements phenomenological simulations we demonstrate magnetic-field-induced reorientation needs be taken into account understand linear...
Femtosecond time-resolved x-ray diffraction is employed to study the dynamics of periodic lattice distortion (PLD) associated with charge-density-wave (CDW) in K0.3MoO3. Using a multi-pulse scheme we show ability extend lifetime coherent oscillations PLD about undistorted structure through re-excitation electronic states. This suggests that it possible enter regime where symmetry potential energy landscape corresponds high phase but scattering pathways lead damping are still controllable by...
We present the investigation of a monoclinic compound SeCuO${}_{3}$ using x-ray powder diffraction, magnetization, torque, and electron-spin-resonance. Structurally based analysis suggests that can be considered as three-dimensional network tetramers. The values intratetramer exchange interactions are extracted from temperature dependence susceptibility amount to $\ensuremath{\sim}\phantom{\rule{-0.16em}{0ex}}200$ K. intertetramer coupling leads development long-range antiferromagnetic order...
We have studied the frequency and voltage dependences of voltage-induced torsional strains in orthorhombic ${\text{TaS}}_{3}$ [V. Y. Pokrovskii, S. G. Zybtsev, I. Gorlova, Phys. Rev. Lett. 98, 206404 (2007)] by measuring modulation resonant an rf cavity containing sample. The strain has onset below charge-density-wave (CDW) threshold voltages associated with changes shear compliance resistance, suggesting that is polarization CDW rather than current. Measurements square-wave show very...
We report on the heat capacity investigation of Cu55Hf45−xTix metallic glasses. The most appropriate procedure to estimate low temperature electronic and phonon contributions has been determined. Both exhibit monotonous Ti concentration dependence, demonstrating that there is no relation either electron density states at Fermi level or Debye increased glass forming ability in range x = 15–30. thermodynamic parameters (e.g., reduced temperature) remain better indicators assessing best...
During the last years, femtosecond time-resolved spectroscopy (fsTRS) has become an important new tool to investigate low energy excitations in strongly correlated systems. By studying relaxation pathways linking various degrees of freedom (e.g., electrons, spin, or lattice), interaction strengths between different subsystems can be deduced. Here we report on yet another application fsTRS, where technique is used unambiguously determine nature ground state granular thin films a prototype...
We have studied the charge density wave (CDW) repolarization dynamics in blue bronze by applying square-wave voltages of different frequencies to sample and measuring changes infrared transmittance, proportional CDW strain. The frequency dependence electrotransmittance was fit a modified harmonic oscillator response evolution parameters as functions voltage, position, temperature are discussed. Resonant decrease with distance from current contacts, indicating that resulting delays intrinsic...
We investigated static and dynamic lattice properties in a quasi-one-dimensional charge-ordered semiconductor ${({\mathrm{NbSe}}_{4})}_{3}\mathrm{I}$ by using Raman, femtosecond pump-probe spectroscopy x-ray diffraction. In addition to well-documented pseudo-Jahn-Teller ferrodistortive structural transition at ${T}_{C}=274$ K, where the displacements of Nb ions lead ferroelectric (FE) in-chain polarization with opposite direction adjacent chains, all methods suggest an additional lowering...
We have studied the dependence of low electric field conductivity charge density wave (CDW) system o-TaS3 on temperature and applied history. Without application high fields, is higher cooling than heating in a wide range below CDW transition. With increasing at given evolves towards stable, history-independent value situated between values. The evolution gradual but most pronounced around threshold for nonlinear conductivity. relative change after asymmetric respect discuss results within...
Single crystalline lead-substituted barium hexaferrite compounds are studied in a broad spectral range, 10 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> Hz to 2*10 xmlns:xlink="http://www.w3.org/1999/xlink">14</sup> Hz. We observe excitations of different nature including dielectric and magnetic relaxations coexisting within the same frequency temperature ranges electronic transitions between fine-structure components split Fe + ground...
We have measured the thermoelectric power of charge density wave system $o$-TaS$_{3}$ in a wide temperature range between 10 K and 300 K. All features characteristic for systems been observed; strong increase below transition $T_{P}$, peak at $T_{M}\sim$1/2-1/3 $T_{P}$ change sign lower temperatures. These can be explained by two contributions; free carriers drag optical phonons with frequencies close to gap value region above, hopping localized opposite low argue that these are common...
The low frequency dielectric response of the charge density wave (CDW) system o-TaS 3 exhibits a rate-independent hysteresis on temperature cycling in very wide range below CDW transition temperature.The ac conductivity, related to dynamics, is higher heating than cooling, while dc conductivity residual free carriers lower, indicating nontrivial relation between two them.Both amplitude and relaxation time process observed region are heating, with similar dependence resistivity.The results...