A5003530284- High-pressure geophysics and materials
- Geological and Geochemical Analysis
- Advanced Condensed Matter Physics
- Magnetic Properties and Synthesis of Ferrites
- Multiferroics and related materials
- Crystallography and Radiation Phenomena
- earthquake and tectonic studies
- Physics of Superconductivity and Magnetism
- Magnetic properties of thin films
- Magnetic Properties and Applications
- Geochemistry and Geologic Mapping
- Methane Hydrates and Related Phenomena
- Iron oxide chemistry and applications
- Geological and Geophysical Studies
- Electrical and Thermal Properties of Materials
- Earthquake Detection and Analysis
- Magnetic and transport properties of perovskites and related materials
- Advanced ceramic materials synthesis
- Microstructure and Mechanical Properties of Steels
- Electronic and Structural Properties of Oxides
- Magneto-Optical Properties and Applications
- Microwave Dielectric Ceramics Synthesis
- Quantum and electron transport phenomena
- Hydrogen Storage and Materials
- Crystal Structures and Properties
University of Bayreuth
2015-2024
Lund University
2021-2023
Malmö University
2023
Rutgers, The State University of New Jersey
2020-2021
Ultrathin SrRuO${}_{3}$ has a nontrivial Hall response that looks strikingly like skyrmion-induced topological effect. Here, the authors demonstrate how Berry phase alone, without skyrmions, provides comprehensive explanation for such response. The contribution to effect can be altered, enhanced, and even change sign in number of layers, temperature, and, importantly, disorder. By comparing effects disorder, theoretically, on skyrmion model spin-orbit coupled model, only latter capture...
A portable double-sided pulsed laser heating system for diamond anvil cells has been developed that is able to stably produce pulses as short a few microseconds with repetition frequencies up 100 kHz. In situ temperature determination possible by collecting and fitting the thermal radiation spectrum specific wavelength range (particularly, between 650 nm 850 nm) Planck function. Surface information can also be time-resolved using gated detector synchronized pulse modulation space-resolved...
Laser heating in a diamond anvil cell (DAC) is common method for studying material behavior at high-pressure and high-temperature conditions. It has been previously proven that during continuous wave (CW) laser of sample, carbon the anvils mobilized, its diffusion into sample can lead to undesirable chemical reactions, which, if not detected, may cause misinterpretations results experiment. Minimizing time with use pulsed (PL) thought reduce risk possible contamination sample; however, this...
The magnetic and electronic structures of Fe
Developments in pulsed laser heating applied to nuclear resonance techniques are presented together with their applications studies of geophysically relevant materials. Continuous diamond anvil cells is a widely used method generate extreme temperatures at static high pressure conditions order study the structure and properties materials found deep planetary interiors. The technique has advantages over continuous heating, including prevention spreading heated sample and/or medium and, thus,...
Abstract Carbonates play an important role in the transport and storage of carbon Earth’s mantle. However, abundance carbonates subduction zones is still unknown quantity. To determine most abundant accessory phases how they influence dynamical processes that operate within Earth, investigations on vibrational, elastic, thermodynamic properties these are crucial for interpreting seismological observations. Recently, nuclear inelastic scattering (NIS) method has proved to be a useful tool...
Abstract Fe1-xO, although chemically simple, possesses a complex structural and magnetic phase diagram. The crystal structures of Fe1-xO its properties at high-pressure high-temperature conditions are still matter debate. In this work, we performed systematic investigation on Fe0.94O up to 94 GPa 1700 K using synchrotron X-ray diffraction Mössbauer source spectroscopy. We observe transition the monoclinic phases above 40 high temperatures use group theory analysis observed discuss their...
Skiagite-Fe-majorite garnets were synthesized using a multianvil apparatus at 7.5–9.5 GPa and 1400–1600 K. Single-crystal X-ray diffraction ambient conditions revealed that contain 23 to 76% of an Fe-majorite component. We found the substitution Fe2+ Si4+ for Fe3+ in octahedral site decreases unit-cell volume garnet conditions. Analysis single-crystal data collected on compression up 90 with different compositions reveals increasing majorite component bulk modulus increases from 159(1)...
Mössbauer spectroscopy (MS) measurements were conducted on ammonium iron formate, [NH4][Fe(HCOO)3] (AFeF), and dimethylammonium [(CH3)2NH2][Fe(HCOO)3] (DMAFeF), under non-ambient conditions. The electric ordering of the NH4+ DMA cations is correlated with changes in local environment, which could have implications for magnetoelectric coupling. In particular, MS was collected upon cooling to 5 K, compression up 10 GPa, both compression. case AFeF, ferroelectric showed no change hyperfine...
GeCu$_2$O$_4$ is a high-pressure recoverable cuprate with strongly tetragonally elongated spinel structure and magnetic lattice formed by $S=1/2$ CuO$_2$ linear chains frustrated exchange interactions exotic behavior. Here we report on the first stabilization of epitaxial thin films (001)-oriented MgAl$_2$O$_4$ substrate. Developed growth mode, surface morphology, crystal copper valence state were characterized \emph{in-situ} reflection high-energy electron diffraction, atomic force...
High pressure can provoke spin transitions in transition metal-bearing compounds. These are of high interest not only for fundamental physics and chemistry, but also may have important implications geochemistry geophysics the Earth planetary interiors. Here we carried out a comparative study pressure-induced compounds with trivalent iron, octahedrally coordinated by oxygen. High-pressure single-crystal Mössbauer spectroscopy data FeBO$_3$, Fe$_2$O$_3$...
During the last decade of high-pressure research a whole new series iron oxides was discovered, like Fe$_4$O$_5$, Fe$_5$O$_6$, Fe$_7$O$_9$ etc., featuring closely related structures with arrays one-dimensional (1D) chains trigonal prisms embedded between slabs octahedra. Here, we develop unified approach to based on specific crystallographic generation mechanism which predicts these and naturally classifies them in terms slab cycle. When including magnetic interactions, show that 1D have...
Abstract The structure and properties of metal-hydrides at extreme conditions is key to the understanding hydrogen-storage technologies, high-temperature superconductivity, dynamics planetary cores. Here we investigate phase relations magnetic iron hydrides, including two novel FeH x compounds, up 63 GPa 1800 K by Synchrotron Mössbauer Source spectroscopy single-crystal X-ray diffraction. We observe formation a monoclinic hydride Fe 2 H ∼3 1000 K, which breaks down stoichiometric hexagonal...