A5025772533- Magnetic and transport properties of perovskites and related materials
- Magnetic properties of thin films
- Multiferroics and related materials
- Advanced Condensed Matter Physics
- High Entropy Alloys Studies
- ZnO doping and properties
- Electronic and Structural Properties of Oxides
- Metallic Glasses and Amorphous Alloys
- Rare-earth and actinide compounds
- High-Temperature Coating Behaviors
- X-ray Diffraction in Crystallography
- Crystallization and Solubility Studies
- Thin-Film Transistor Technologies
- Magnetic Properties of Alloys
- Nanowire Synthesis and Applications
- Ferroelectric and Piezoelectric Materials
- Advanced Memory and Neural Computing
- Semiconductor materials and devices
- Copper-based nanomaterials and applications
- Magnetic Properties and Applications
- Nanoporous metals and alloys
- Physics of Superconductivity and Magnetism
- Gas Sensing Nanomaterials and Sensors
- Magnetic Properties and Synthesis of Ferrites
- Advanced Sensor and Energy Harvesting Materials
Karlsruhe Institute of Technology
2016-2025
Technical University of Darmstadt
2008-2022
Nanjing University of Science and Technology
2021
University of Duisburg-Essen
2008-2020
Karlsruhe University of Education
2015
Helmholtz-Zentrum Dresden-Rossendorf
2008
Institute of Nuclear Physics, Polish Academy of Sciences
1991-2006
Northern Illinois University
2000-2003
Commissariat à l'Énergie Atomique et aux Énergies Alternatives
1998
CEA Grenoble
1998
We report a facile particle mediated aggregation protocol to synthesize "sea urchin"-like gold mesoparticles with tailored surface topography via secondary nucleation and growth process. Surprisingly, these multitip Au are capable of self-assembling into monolayer or multiple layer arrays on Si substrates convincing reproducibility homogeneity over large areas. Raman measurements show that individual sea urchin-like multitipped exhibit high enhancement surface-enhanced scattering (SERS). In...
Abstract The enhanced compositional flexibility to incorporate multiple-principal cations in high entropy oxides (HEOs) offers the opportunity expand boundaries for accessible compositions and unconventional properties oxides. Attractive functionalities have been reported some bulk HEOs, which are attributed long-range homogeneity, lattice distortion, local chemical bonding characteristics materials. However, intricate details of composition fluctuation, metal-oxygen bond distortion...
Unraveling the mechanism behind bulk perpendicular magnetic anisotropy (PMA) in amorphous rare earth-transition metal films has proven challenging. This is largely due to inherent complexity of structure and entangled potential origins arising from microstructure atomic factors. Here, we present an approach wherein magneto-electric effect harnessed induce 90° switching PMA Tb–Co in-plane directions by applying voltages only −1.2 V. manipulation achieved voltage-driven insertion hydrogen...
The crystal and magnetic structures of newly synthesized ${\mathrm{Sr}}_{1\ensuremath{-}x}{\mathrm{Ca}}_{x}{\mathrm{MnO}}_{3}$ $(0<~x<~1)$ ${\mathrm{Sr}}_{1\ensuremath{-}y}{\mathrm{Ba}}_{y}{\mathrm{MnO}}_{3}$ $(y<~0.2)$ perovskite materials (of the $\mathrm{AB}{\mathrm{O}}_{3}$ type) were investigated using neutron synchrotron x-ray powder diffraction at temperatures between 10 530 K. Upon decreasing size A-site ion (or unit-cell size) a series structural transitions appears room...
The nuclear and magnetic structures of ${\mathrm{Sr}}_{2}{\mathrm{FeMoO}}_{6}$ have been investigated using neutron powder diffraction M\"ossbauer spectroscopy at temperatures between 10 460 K. Fe Mo atoms are found to order on alternate sites, as expected, giving rise a double-perovskite-type unit cell. Upon cooling, structural phase transition from cubic $\mathrm{Fm}3\ifmmode\bar\else\textasciimacron\fi{}m$ tetragonal $I4/m$ occurs \ensuremath{\sim}400 In the structure temperature...
Printed electronics (PE) represents any electronic devices, components or circuits that can be processed using modern-day printing techniques. Field-effect transistors (FETs) and logics are being printed with intended applications requiring simple circuitry on large, flexible (e.g., polymer) substrates for low-cost disposable electronics. Although organic materials have commonly been chosen their easy printability low temperature processability, high quality inorganic oxide-semiconductors...
It has been shown that oxide ceramics containing multiple transition and/or rare-earth elements in equimolar ratios have a strong tendency to crystallize simple single-phase structures, stabilized by the high configurational entropy. In analogy metallic alloy systems, these oxides are denoted high-entropy (HEOs). The HEO concept allows access hitherto uncharted areas multielement phase diagram. Among already realized structures there is highly complex class of element perovskites. This...
An extension in magnetoelectric effects is proposed to include reversible chemistry-controlled magnetization variations. This ion-intercalation-driven magnetic control can be fully and pertinent bulk material volumes. The concept demonstrated for ferromagnetic iron oxide where the intercalated lithium ions cause valence change partial redistribution of Fe3+ cations yielding a large at room temperature. As service our authors readers, this journal provides supporting information supplied by...
This Frontier article highlights the distinctive magnetic properties of high entropy oxides and possible research directions for future explorations.
Abstract Layered Delafossite-type Li x (M 1 M 2 3 4 5 …M n )O materials, a new class of high-entropy oxides, were synthesized by nebulized spray pyrolysis and subsequent high-temperature annealing. Various metal species = Ni, Co, Mn, Al, Fe, Zn, Cr, Ti, Zr, Cu) could be incorporated into this structure type, in most cases, single-phase oxides obtained. Delafossite structures are well known the related materials used different fields application, especially electrochemical energy storage...
Novel high entropy ceramics, fluorides, are introduced. The microstructure and solid solution state of the material thoroughly characterized. Additionally, promising catalytic activity for oxygen evolution reaction was observed.
High entropy oxides (HEOs) are single-phase solid solutions consisting of 5 or more cations in approximately equiatomic proportions. In this study, we show the reversible control optical properties a rare-earth (RE) based HEO-(Ce0.2La0.2Pr0.2Sm0.2Y0.2)O2−δ and subsequently utilize combination spectroscopic techniques to derive features electronic band structure underpinning observed phenomena. Heat treatment HEO under vacuum atmosphere followed by reheat air results change bandgap energy,...
Technologically relevant strongly correlated phenomena such as colossal magnetoresistance (CMR) and metal-insulator transitions (MIT) exhibited by perovskite manganites are driven enhanced the coexistence of multiple competing magneto-electronic phases. Such inhomogeneity is governed intrinsic lattice-charge-spin-orbital correlations, which, in turn, conventionally tailored via chemical substitution, charge doping, or strain engineering. Alternately, recently discovered high entropy oxides...
Abstract Single‐crystal, 1D nanostructures are well known for their high mobility electronic transport properties. Oxide‐nanowire field‐effect transistors (FETs) offer both optical transparency and large mechanical conformability which essential flexible transparent display applications. Whereas the “on‐currents” achieved with nanowire channel already sufficient to drive active matrix organic light emitting diode (AMOLED) displays; it is shown here that incorporation of...
The possibility to synthesize bulk amorphous materials with an internal nanostructure—nanoglasses—leads yet another class of potentially modified properties. Here, evidence is presented that the nanoglass model system Fe90Sc10 exhibits enhanced magnetic properties: it shown this (prepared by cold compaction glassy nanospheres) a ferromagnet at ambient temperature although isolated nanospheres are paramagnetic. Structural studies reveal consists connected regions reduced atomic density....
Critical prerequisites for solution-processed/printed field-effect transistors (FETs) and logics are excellent electrical performance including high charge carrier mobility, reliability, environmental stability low/preferably room temperature processing. Oxide semiconductors can often fulfill all the above criteria, sometimes even with better promise than their organic counterparts, except process requirement. The need annealing/curing temperatures renders oxide FETs rather incompatible to...
The magnetoelectric effect, i.e., electric‐field control of magnetism in artificial heterostructures is usually limited to surface/interface atoms the magnetic materials. In order attain electrical bulk ferromagnets, this study proposes extend definition phenomena include reversible, chemistry‐controlled magnetization switching. A large and reversible change room temperature strong ferromagnets reported, with electrochemistry‐driven Li‐ion exchange; carefully chosen spinel ferrites...
Abstract Solution‐processed or printed n‐channel field‐effect transistors (FETs) with high performance are not reported very often in the literature due to scarcity of high‐mobility n‐type organic semiconductors. On other hand, low‐temperature processed metal oxide semiconductor (NMOS) from electron conducting inorganic‐oxide nanoparticles show reduced‐performance and low mobility because large channel roughness at channel‐dielectric interface. Here, a method produce ink‐jet NMOS transistor...
Complementary metal oxide semiconductor (CMOS) technology with high transconductance and signal gain is mandatory for practicable digital/analog logic electronics. However, performance all-oxide CMOS logics are scarcely reported in the literature; specifically, not at all solution-processed/printed transistors. As a major step toward solution-processed electronics, here it shown that using highly efficient electrolyte-gating approach one can obtain printed low-voltage operated (≈21 supply...
Inkjet printed and low voltage (≤1 V) driven field-effect transistors (FETs) are prepared from precursor-made In2O3 as the transistor channel a composite solid polymer electrolyte (CSPE) gate dielectric. Printed halide precursors annealed at different temperatures (300-500 °C); however, devices that heated to 400 °C demonstrate best electrical performance including mobility high 126 cm(2) V(-1) s(-1) subthreshold slope (68 mV/dec) close theoretical limit. These outstanding device...
Abstract Electric field tuning of magnetism is one the most intensely pursued research topics recent times aiming at development new-generation low-power spintronics and microelectronics. However, a reversible magnetoelectric effect with an on/off ratio suitable for easy precise device operation yet to be achieved. Here we propose novel route robustly tune via charging/discharging processes hybrid supercapacitors, which involve electrostatic (electric-double-layer capacitance)...
By use of a metallo-supramolecular concept, linear iron(II) coordination chain [FeII(L)]n(BF4)2n (L = 1,4-bis(1,2′:6′,1″-bispyrazolylpyridin-4′-yl)benzene) was rationally designed and synthesized. The molecular shows reversible spin transition at 323 K with ca. 10 wide hysteresis loop.