A5068902744- Advanced Condensed Matter Physics
- Physics of Superconductivity and Magnetism
- Magnetic and transport properties of perovskites and related materials
- Theoretical and Computational Physics
- Multiferroics and related materials
- Magnetic properties of thin films
- Nuclear Physics and Applications
- Rare-earth and actinide compounds
- High-pressure geophysics and materials
- Iron-based superconductors research
- Metallic Glasses and Amorphous Alloys
- 2D Materials and Applications
- Atomic and Subatomic Physics Research
- Magnetic Properties and Applications
- Magnetic Properties of Alloys
- DNA and Nucleic Acid Chemistry
- Nuclear materials and radiation effects
- Organic and Molecular Conductors Research
- Thermodynamic and Structural Properties of Metals and Alloys
- Quantum, superfluid, helium dynamics
- Inorganic Fluorides and Related Compounds
- Solid-state spectroscopy and crystallography
- Quantum and electron transport phenomena
- Crystal Structures and Properties
- Crystallization and Solubility Studies
Institut Laue-Langevin
2016-2025
Paul Scherrer Institute
2011-2021
University of Geneva
2021
University of Cambridge
2018
BP (United Kingdom)
2016
CEA Grenoble
2000-2016
Forschungszentrum Jülich
2015
Devi Ahilya Vishwavidyalaya
2011
UGC DAE Consortium for Scientific Research
2011
Institut Langevin
1999-2010
Magnetic Monopoles Magnets come with a north and south pole. Despite being predicted to exist, searches in astronomy high-energy particle physics experiments for magnetic monopoles (either or on their own) have defied observation. Theoretical work condensed-matter systems has that spin-ice structures may harbor such elusive particles (see the Perspective by Gingras ). Fennell et al. (p. 415 , published online 3 September) Morris 411 used polarized neutron scattering probe spin structure...
Using various macroscopic and microscopic techniques, including magnetometry neutron x-ray diffraction measurements, the authors investigate magnetic properties of quasi-two-dimensional antiferromagnet NiPS${}_{3}$. Contrary to previous find that material orders antiferromagnetically with a propagation vector $\mathbf{k}$=[010]. This clarification structure is hoped lead better understanding overall dynamics in these types systems.
Neutron scattering from single crystals has been used to determine the magnetic structure and magnon dynamics of ${\text{FePS}}_{3}$, an $S=2$ Ising-like quasi-two-dimensional antiferromagnet with a honeycomb lattice. The confirmed have propagation vector ${\mathbf{k}}_{M}=\left[01\frac{1}{2}\right]$ moments are collinear normal $ab$ planes. data could be modeled using Heisenberg Hamiltonian single-ion anisotropy. Magnetic interactions up third in-plane nearest neighbor needed included for...
The pyrochlore material Ho2Ti2O7 has been suggested to show "spin ice" behavior. We present neutron scattering and specific heat results that establish unambiguously exhibits spin ice correlations at low temperature. Diffuse magnetic is quite well described by a nearest neighbor model very accurately dipolar model. capacity accounted for the sum of contribution an expected nuclear contribution, known exist in other Ho3+ salts. These settle question nature temperature which contradictory...
Er_2Ti_2O_7 has been suggested to be a realization of the frustrated < 111 > XY pyrochlore lattice antiferromagnet, for which theory predicts fluctuation-induced symmetry breaking in highly degenerate ground state manifold. We present theoretical analysis classical model compared neutron scattering experiments on real material, both below and above T_N = 1.173(2) K. The correctly ordered magnetic structure, suggesting that system order stabilised by zero-point quantum fluctuations can...
We have revisited the magnetic structure of manganese phosphorus trisulfide MnPS3 using neutron diffrac- tion and polarimetry. undergoes a transition toward collinear antiferromagnetic order at 78 K. The resulting point-group breaks both time reversal space inversion thus allowing linear magnetoelectric coupling. Neutron polarimetry was subsequently used to prove that this coupling provides way manipulate domains simply by cooling sample under crossed electrical fields, in agreement with...
In 2017, we discovered quaternary i-MAX phases—atomically layered solids, where M is an early transition metal, A group element, and X C—with a (M12/3M21/3)2AC chemistry, the M1 M2 atoms are in-plane ordered. Herein, report discovery of class magnetic phases in which bilayers quasi-2D frustrated triangular lattice overlay Mo honeycomb arrangement Al Kagomé lattice. The chemistry this family (Mo2/3RE1/3)2AlC, rare-earth, RE, elements Ce, Pr, Nd, Sm, Gd, Tb, Dy, Ho, Er, Tm, Lu. properties were...
The magnetic properties and structure are presented for CoPS$_3$, a quasi-two-dimensional antiferromagnet on honeycomb lattice with N\'eel temperature of $T_N \sim 120$ K. compound is shown to have XY-like anisotropy in its susceptibility, the analysed extract crystal field parameters. For temperatures between 2 K 300 K, no phase transitions were observed field-dependent magnetization up 10 Tesla. Single-crystal neutron diffraction shows that propagation vector {\bf{k}}= $\left[010\right]$...
Two-dimensional materials have proven to be a prolific breeding ground of new and unstudied forms magnetism unusual metallic states, particularly when tuned between their insulating phases. In this paper we present work on metal insulator transition system FePS$_3$ . This compound is two-dimensional van-der-Waals antiferromagnetic Mott insulator. Here report the discovery an insulator-metal in FePS$_3$, as evidenced by x-ray diffraction electrical transport measurements, using high pressure...
Neutron inelastic scattering has been used to measure the magnetic excitations in powdered ${\mathrm{NiPS}}_{3}$, a quasi-two-dimensional antiferromagnet with spin $S=1$ on honeycomb lattice. The spectra show clear, dispersive magnons $\ensuremath{\sim}7$ meV gap at Brillouin zone center. data were fitted using Heisenberg Hamiltonian single-ion anisotropy assuming no exchange between planes. Magnetic interactions up third intraplanar nearest neighbor required. fits robustly that...
Neutron spectroscopy measurements have been performed on single crystals of the antiferromagnetic van der Waals compound NiPS$_3$. Linear spin wave theory using a Heisenberg Hamiltonian with single-ion anisotropies has applied to determine magnetic exchange parameters and nature anisotropy. The analysis reveals that NiPS$_3$ is less two-dimensional than its sister compounds, relatively large ferromagnetic $J^{\prime} = -0.3$ meV between layered \emph{ab} planes. In-plane interactions up...
Inelastic neutron scattering from a single crystal of the quasi-two-dimensional antiferromagnet has been used to measure spin wave dispersion curve at 4 K. The exchange integrals were subsequently calculated linear theory. values meV, meV and are within stability conditions mean-field In addition, critical behaviour gap in energy Brillouin zone centre measured, compared magnetization data magnetic (020) Bragg peak. varies with for , square . Two possible explanations proposed: competition...
A comprehensive study of the static and dynamic critical properties quasi-two-dimensional antiferromagnet ${\mathrm{MnPS}}_{3}$ is presented. The relatively large spin $S=5∕2$ Mn ions ensure predominantly classical behavior, compound believed to be a good example Heisenberg-type system on honeycomb lattice. sample has been measured using variety neutron-scattering techniques instrumentation. results are compared three-dimensional (3D) Heisenberg model, two-dimensional $\mathrm{O}(3)$ rotator...
The spin waves in a powdered sample of quasi-two-dimensional antiferromagnet, FePS(3), have been measured using neutron inelastic scattering. data could be modelled and the exchange interactions determined two-dimensional Heisenberg Hamiltonian with single ion anisotropy. A suitable fit to only achieved by including magnetic up third nearest neighbour, which is consistent findings for other members MPS(3) family (M=transition metal). best parameters at 6 K were J(1) = 1.49 meV, J(2) 0.04...
A prototypical quasi-2D metallic compound, 1T-TaS_2 has been extensively studied due to an intricate interplay between a Mott-insulating ground state and charge density-wave (CDW) order. In the low-temperature phase, 12 out of 13 Ta_{4+} 5\textit{d}-electrons form molecular orbitals in hexagonal star-of-David patterns, leaving one 5\textit{d}-electron with \textit{S} = 1/2 spin free. This orphan quantum large spin-orbit interaction is expected highly correlated phase its own. And it most...
The vertical sample-plane reflectometer D17 at the Institut Laue–Langevin in Grenoble, France, has undergone several major upgrades since its commissioning, which are summarized this article. three improvements (i) a new focusing guide, increasing usable flux on sample by factor of 2.5; (ii) beam polarizer and spin flippers, allowing for use polarized neutrons time-of-flight mode; (iii) detector with particularly uniform response under homogeneous exposure, improved stability...
Abstract The pseudo-gap phenomenon in copper oxide superconductors is central to any description of these materials as it prefigures the superconducting state itself. A magnetic intra-unit-cell order was found occur just at temperature four cuprate high- T c families. Here we present polarized neutron-scattering measurements nearly optimally doped YBa 2 Cu 3 O 6.85 , carried out on two different spectrometers, that reveal several features. consists finite-sized planar domains are very weakly...
Layered van-der-Waals 2D magnetic materials are of great interest in fundamental condensed-matter physics research, as well for potential applications spintronics and device physics. We present neutron powder diffraction data using new ultra-high-pressure techniques to measure the structure Mott-insulating honeycomb antiferromagnet FePS$_3$ at pressures up 183 kbar temperatures down 80 K. These complemented by high-pressure magnetometry reverse Monte Carlo modeling spin configurations. As...
We study the enhanced magnetic moment observed in epitaxial magnetite $({\text{Fe}}_{3}{\text{O}}_{4})$ ultrathin films $(t<15\text{ }\text{nm})$ grown on MgO (001) substrates by means of pulsed laser deposition. The ${\text{Fe}}_{3}{\text{O}}_{4}$ thin exhibit high crystallinity, low roughness, and sharp interfaces with substrate, existence Verwey transition at thicknesses down to 4 nm. evolution temperature film thickness shows a dependence antiphase boundaries density. Superconducting...
Poly(2-(dimethylamino)ethyl methacrylate) (PDMAEMA) brushes have been grown by surface-initiated atom transfer radical polymerization (SI-ATRP) from the gold–water interface at different grafting densities, and neutron reflectivity has used to characterize response of brush structures changes in pH temperature. Low-density show greatest pH, with swelling highest density essentially independent pH. The scaling exponent ratio β ∼ −0.7, which is typical for neutral brushes, 10, −1.4, 3,...
We present an overview of our recent work in tuning and controlling the structural, magnetic electronic dimensionality 2D van-der-Waals antiferromagnetic compounds (Transition-Metal)PS3. Low-dimensional systems such as these provide rich opportunities for studying new physics evolution established behaviours with changing dimensionality. These materials can be exfoliated to monolayer thickness easily stacked combined into functional heterostructures. Alternatively, application hydrostatic...