A5032561474- Magnetic and transport properties of perovskites and related materials
- Advanced Condensed Matter Physics
- Physics of Superconductivity and Magnetism
- Electronic and Structural Properties of Oxides
- Inorganic Fluorides and Related Compounds
- Multiferroics and related materials
- Advancements in Solid Oxide Fuel Cells
- Catalytic Processes in Materials Science
- Advancements in Battery Materials
- Advanced Photocatalysis Techniques
- Catalysis and Oxidation Reactions
- Inorganic Chemistry and Materials
- Semiconductor materials and devices
- Magneto-Optical Properties and Applications
- Luminescence Properties of Advanced Materials
- Crystal Structures and Properties
- Advanced Battery Materials and Technologies
- Ferroelectric and Piezoelectric Materials
- Extraction and Separation Processes
- Heavy metals in environment
- Copper-based nanomaterials and applications
- Advanced battery technologies research
- Carbon Nanotubes in Composites
- ZnO doping and properties
- Metal-Organic Frameworks: Synthesis and Applications
European Synchrotron Radiation Facility
2021-2024
Technical University of Darmstadt
2019-2021
University of Stuttgart
2021
Centro Brasileiro de Pesquisas Físicas
2017-2019
Aalto University
2010-2019
École Polytechnique Fédérale de Lausanne
2016
The University of Texas at Austin
2012
A quantum spin liquid state has long been predicted to arise in spin-1/2 Heisenberg square-lattice antiferromagnets at the boundary region between Néel (nearest-neighbor interaction dominates) and columnar (next-nearest-neighbor antiferromagnetic order. However, there are no known compounds this region. Here we use d
The first multi-transition metal cathode was examined for fluoride ion batteries, showing different redox behaviour of cobalt and nickel on charging discharging.
The spin-1/2 square-lattice Heisenberg model is predicted to have a quantum disordered ground state when magnetic frustration maximized by competing nearest-neighbor ${J}_{1}$ and next-nearest-neighbor ${J}_{2}$ interactions $({J}_{2}/{J}_{1}\ensuremath{\approx}0.5)$. double perovskites $\mathrm{S}{\mathrm{r}}_{2}\mathrm{CuTe}{\mathrm{O}}_{6}$ $\mathrm{S}{\mathrm{r}}_{2}\mathrm{CuW}{\mathrm{O}}_{6}$ are isostructural antiferromagnets with N\'eel $({J}_{1}$ dominates) columnar $({J}_{2}$...
We report the synthesis of bulk RE1-xAxNiO3 (RE = La, Nd ; A Sr, Ca) perovskite phases under high oxygen pressure (T 900 °C, PO2 250 bars) and identified a solubility limit x 0.07 for phase-pure samples. This limit, shared by various RE combination investigated is likely constrained Ni4+ content (t26) whose electronic effect limits doping, regardless size atoms. Alkaline earth (hole) doping induces decrease in volume unit cell RE1-xAxNiO3, despite presence larger alkaline atoms, an increase...
Abstract Electrical tuning of materials' magnetic properties is great technological interest, and in particular reversible on/off switching ferromagnetism can enable various new applications. Reversible magnetization the ferromagnetic Ruddlesden–Popper manganite La 2−2 x Sr 1+2 Mn 2 O 7 by electrochemical fluoride‐ion (de)intercalation an all‐solid‐state system demonstrated for first time. A 67% change relative observed with a low operating potential <1 V, negligible capacity fading, high...
Within this study, we show that a broad range of reduced phases La2NiO3F2−Δ can be derived from Ruddlesden–Popper-type La2NiO3F2 using reductive topochemical defluorination method based on reactions between the oxyfluoride and sodium hydride. The selective extraction fluoride results in strong structural changes, nuclear magnetic structures obtained have been determined. Due to high anion content La2NiO3F2, formation Ni+-containing compounds has observed under reduction. For first time, led...
Establishing the physical mechanism governing exchange interactions is fundamental for exploring exotic phases such as quantum spin liquids in real materials. In this Letter, we address ${\mathrm{Sr}}_{2}{\mathrm{CuTe}}_{x}{\mathrm{W}}_{1\ensuremath{-}x}{\mathrm{O}}_{6}$, a series of double perovskites that realize spin-$1/2$ square lattice and are suggested to harbor liquid ground state arising from random distribution nonmagnetic ions. Our ab initio multireference configuration interaction...
In this work we examine the low-temperature magnetic properties of two double-perovskite compounds ${\mathrm{Sr}}_{2}$${\mathrm{CuWO}}_{6}$ and ${\mathrm{Sr}}_{2}$${\mathrm{CuMoO}}_{6}$ using susceptibility, muon spin rotation relaxation, neutron powder diffraction measurements. Additionally, most relevant exchange interaction constants are derived from ab initio electronic structure calculations, aided by x-ray absorption spectroscopy. The exhibit quasi-two-dimensional properties, with...
Here, we report the synthesis of double-perovskite system Sr2Cu(W1–xMox)O6, with x = 0.0–1.0, where Mo-containing members have not been synthesized before. This provides an example a quasi-two-dimensional S 1/2 square lattice, possibility magnetic frustration. The compounds were under ambient pressure for 0 ≤ 0.6 and high (HP) 0.7 1.0. A small percentage impurities, primarily Sr(W,Mo)O4, was present in all samples increased ≥ 0.5. Tetragonal distortion decreases increasing x,...
Magnetic structure of the double perovskite Sr2CuWO6 was determined from neutron powder diffraction data. At 3 K material is magnetically long-range ordered into a collinear antiferromagnetic described by propagation vector k = (0, 1/2, 1/2) with CuII moments 0.57(1) μB parallel to a-axis. The result in agreement our previous prediction (Vasala et al 2014 Phys. Rev. B 89 134419) based on electronic calculations, showing that three-dimensional magnetic order caused relatively strong...
${\text{Sr}}_{2}{\text{CuWO}}_{6}$ is a double perovskite proposed to be at the border between two- and three-dimensional magnetism, with square lattice of $S=\frac{1}{2}\phantom{\rule{4pt}{0ex}}{\mathrm{Cu}}^{2+}$ ions. We have used inelastic neutron scattering investigate spin wave excitations system, find out how they evolve as function temperature, well obtain information about magnetic exchange interactions. observed defined dispersive modes 6 K, which partially survive above ordering...
Here we report the results of structural, microstructural and magnetic property characterizations both thin films bulk samples LaMnO3 (LMO). Thin were deposited by atomic layer deposition technique on silicon (1 0 0) substrates, whereas prepared a citrate combustion route. Effects varying thickness, annealing atmosphere temperature studied LMO sample classes. Single-phase perovskite crystal structure was confirmed x-ray diffraction Raman spectroscopy, in annealed at 700 800 °C as well...
We present a comprehensive computational and experimental examination of the $\mathrm{C}{\mathrm{r}}_{1\ensuremath{-}x}{\mathrm{V}}_{x}{\mathrm{O}}_{2} (0\ensuremath{\le}x\ensuremath{\le}0.5)$ system. The entire series crystallizes in rutile structure, but compounds exhibit significantly different magnetic properties depending on $x$. Lattice parameter $a$ increases linearly with $x$, $c$ is slightly reduced due to vanadium-vanadium bonding. V-for-Cr substitution creates...
Understanding high-temperature unconventional superconductivity has become a long-lasting problem in which the cuprates stand as central reference materials. Given this impasse, recent discovery of analogous nickelate thin films represents fundamental breakthrough calling for identification additional materials class. In particular, thermodynamically more robust systems are required to "upgrade" superconductors from bulk samples. Here, we contribute direction by reporting synthesis new...
The isostructural double perovskites Ba2CuTeO6 and Ba2CuWO6 are shown by theory experiment to be frustrated square-lattice antiferromagnets with opposing dominant magnetic interactions. This is driven differences in orbital hybridisation of Te6+ W6+. A spin-liquid-like ground state predicted for Ba2Cu(Te1-xWx)O6 solid solution similar recent observations Sr2Cu(Te1-xWx)O6.
Multivariate data analysis is used in search of novel magnetically ordered perovskite oxides the A<sub>2</sub>B′B′′O<sub>6</sub> type.
Advanced deposition routes are vital for the growth of functional metal–organic thin films. The gas-phase atomic/molecular layer (ALD/MLD) technique provides solvent-free and uniform nanoscale films with unprecedented thickness control allows straightforward device integration. Most excitingly, ALD/MLD can enable in situ novel crystalline materials. An exquisite example is iron-terephthalate (Fe-BDC), which one most appealing framework (MOF) type materials thus widely studied bulk form owing...