A5085915283- Magnetic properties of thin films
- Iron oxide chemistry and applications
- Geomagnetism and Paleomagnetism Studies
- Magnetic Properties and Applications
- Geophysical and Geoelectrical Methods
- Advanced Electron Microscopy Techniques and Applications
- Magnetic Properties and Synthesis of Ferrites
- Electron and X-Ray Spectroscopy Techniques
- Characterization and Applications of Magnetic Nanoparticles
- Theoretical and Computational Physics
- Physics of Superconductivity and Magnetism
- Minerals Flotation and Separation Techniques
- Magnetic Properties of Alloys
- Advanced Memory and Neural Computing
- Metallic Glasses and Amorphous Alloys
- Magnetic and transport properties of perovskites and related materials
- Nuclear Materials and Properties
- Clay minerals and soil interactions
- Nanoparticle-Based Drug Delivery
- Copper-based nanomaterials and applications
- Magnetic and Electromagnetic Effects
- Geological and Geochemical Analysis
- Hydrogen Storage and Materials
- Multiferroics and related materials
- Radioactive element chemistry and processing
University of Glasgow
2016-2025
Commissariat à l'Énergie Atomique et aux Énergies Alternatives
2021-2024
Université Grenoble Alpes
2021-2024
CEA Grenoble
2021-2024
CEA LETI
2021-2023
Scottish Universities Physics Alliance
2022
University of Leeds
2021
Institut polytechnique de Grenoble
2021
Instituto de Geociencias
2020
Universidade de Brasília
2020
Abstract The term “pseudo‐single domain” (PSD) has been used to describe the transitional state in rock magnetism that spans particle size range between single domain (SD) and multidomain (MD) states. for stable SD most commonly occurring terrestrial magnetic mineral, magnetite, is so narrow (~20–75 nm) it widely considered much of paleomagnetic record interest carried by PSD rather than particles. concept has, thus, become dominant explanation magnetization associated with a major fraction...
Significance When magnetic crystals form in rocks and meteorites, they can record the ancient field retain this information over geological timescales. Scientists use these recordings to study evolution of Earth Solar System. Previous theories for recording mechanisms meteorites are based on idea that structures within near uniform. However, from numerous studies we know not be true. The too large size display complex nonuniform “vortex” structures. In have shown vortex capable retaining...
A "process map" for the hydrothermal synthesis (HS) of single crystalline α-Fe2O3 nanorods from aqueous FeCl3 is presented, as a function temperature, time, and phosphate concentration, assessed using combined techniques X-ray diffractometry, transmission electron microscopy, selected area diffraction, Fourier transform infrared spectrometry, photoelectron spectroscopy. The process map provides insight into nature intermediate β-FeOOH nanorod precipitation, dissolution subsequent growth,...
Abstract Magnetite (Fe 3 O 4 ) is an important magnetic mineral to Earth scientists, as it carries the dominant signature in rocks, and understanding of its recording fidelity provides a critical tool field palaeomagnetism. However, reliable interpretation Fe particles greatly diminished over time by progressive oxidation less iron oxides, such maghemite (γ-Fe 2 ), with consequent alteration remanent magnetization potentially having geological significance. Here we use complementary...
In situ electron microscopy is used to visualize the thermomagnetic behavior of vortex domain states within magnetic minerals.
A deiscência anastomótica é uma complicação grave em cirurgias gastrointestinais, associada a aumento da morbimortalidade e necessidade de reintervenção. Métodos convencionais para avaliação perfusão tecidual intraoperatória possuem limitações, tornando essencial busca por técnicas mais precisas. fluorescência indocianina verde (ICG-FI) tem emergido como ferramenta promissora, permitindo visualização tempo real sanguínea possibilitando ajustes intraoperatórios na anastomose. Esta revisão...
Stabilizing magnetic skyrmions is a critical issue in spintronics, impacting data storage and computing. This study investigates skyrmion skyrmionium phenomena within hexagonal array of curved nanomagnets. Utilizing atomistic calculations, micromagnetic simulations, experimental methods such as force microscopy electron holography, we analyze the interplay between parameters, curvature, interfacial Dzyaloshinskii-Moriya interaction (iDMI) formation these structures. We observed that isolated...
The hydrothermal growth mechanism of α-Fe2O3 nanorods has been investigated using a novel valve-assisted pressure autoclave. This approach facilitated the rapid quenching suspensions into liquid nitrogen, providing 'snapshots' representative near in situ physical state synthesis reaction products as function known temperature. Examination acquired samples complementary characterisation techniques transmission electron microscopy, X-ray photoelectron spectroscopy and Fourier transform...
In synthetic antiferromagnets (SAFs), antiferromagnetic (AFM) order and synthesis using conventional sputtering techniques is combined to produce systems that are advantageous for spintronics applications. Here we present the preparation study of SAF multilayers possessing both perpendicular magnetic anisotropy Dzyaloshinskii-Moriya interaction. The have an antiferromagnetically aligned ground state but can be forced into a full ferromagnetic (FM) alignment by applying out-of-plane field...
Abstract Recordings of magnetic fields, thought to be crucial our solar system’s rapid accretion, are potentially retained in unaltered nanometric low-Ni kamacite (~ metallic Fe) grains encased within dusty olivine crystals, found the chondrules unequilibrated chondrites. However, most these magnetically non-uniform, so their ability retain four-billion-year-old recordings cannot estimated by previous theories, which assume only uniform magnetization. Here, we demonstrate that non-uniformly...
Abstract The thermal demagnetization of pseudo‐single‐domain (PSD) magnetite (Fe 3 O 4 ) particles, which govern the magnetic signal in many igneous rocks, is examined using off‐axis electron holography. Visualization a vortex structure held by an individual Fe particle (~250 nm diameter) during situ heating achieved through construction and examination magnetic‐induction maps. Stepwise remanence‐induced upon to above Curie temperature, performed similar fashion bulk measurements, revealed...
Abstract The thermomagnetic behavior of remanence‐induced magnetite (Fe 3 O 4 ) particles in the pseudo‐single‐domain (PSD) size range (~0.1–10 µm), which dominate magnetic signature many rock lithologies, is investigated using off‐axis electron holography. Construction induction maps allowed for visualization vortex domain state an individual Fe grain (~200 nm diameter) as a function temperature. Acquisition series holograms at 100°C intervals during situ heating up to 700°C demonstrates...
In this paper, we report the pyrolysis and formation of magnetic minerals in three source rock samples from Wessex Basin Dorset, southern England. The experimental conditions laboratory recreated catagenesis environment oil rocks. Magnetic analysis both heated unheated at room temperature very low-temperatures (5 K), coupled with transmission electron-microscopy imaging X-ray analysis, revealed nanometre-sized (<10 nm), particles that varied across analysed, but more importantly range....
Equi-atomic FeRh is a very interesting material as it undergoes magnetostructural transition from an antiferromagnetic (AF) to ferromagnetic (FM) phase between 75-105 °C. Its ability present co-existence separated by domain walls (DWs) above room temperature provides immense potential for exploitation of their DW motion in spintronic devices. To be able effectively control the DWs associated with AF/FM coexistence thin films we must fully understand and thermomagnetic behaviour at localised...
The mapping of electrostatic potentials and magnetic fields in liquids using electron holography has been considered to be unrealistic. Here, we show that hydrated cells Magnetospirillum magneticum strain AMB-1 assemblies nanoparticles can studied off-axis a fluid cell specimen holder within the transmission microscope. Considering holographic object reference wave both pass through liquid, recorded holograms sufficient interference fringe contrast permit reconstruction phase shift induction...
Acicular α-Fe2O3 nanorods (NRs), at an intermediate stage of development, were isolated using a snapshot valve-assisted hydrothermal synthesis (HS) technique, for the purpose complementary in situ transmission electron microscopy (iTEM) and environmental TEM (ETEM) investigations effect local environment on oriented attachment (OA) nanoparticles (NPs) during NR growth. Observations static HS samples suggested that NPs undergo reorientation following initial attachment, consistent with OA...
Abstract The effect of maghemization on the magnetic properties magnetite (Fe 3 O 4 ) grains in pseudo‐single‐domain (PSD) size range is investigated as a function annealing temperature. X‐ray diffraction and transmission electron microscopy confirm precursor Fe ranging from ∼150 to ∼250 nm diameter, whilst Mössbauer spectrometry suggests are initially near‐stoichiometric. heated increasing reaction temperatures 120–220°C investigate their oxidation maghemite (γ‐Fe 2 ). High‐angle annular...
To advance the use of thermally-activated magnetic materials in device applications it is necessary to examine their behaviour on localised scale operando conditions. Equi-atomic FeRh undergoes a magnetostructural transition from an antiferromagnetic (AF) ferromagnetic (FM) phase above room temperature (~ 75 105 {\deg}C) and hence considered very desirable material for next generation novel nanomagnetic or spintronic devices. For this be realised, we must fully understand intricate details...
A unique new class of core–shell structured composite nanoparticles, C-coated inorganic fullerene-like WS2 (IF-WS2) hollow has been created for the first time in large quantities, by a continuous chemical vapour deposition method using rotary furnace. Transmission electron microscopy and Raman characterisations resulting samples reveal that nanoparticles exhibited uniform shell carbon coating, ranging from 2–5 nm on IF-WS2 core, with little or no agglomeration. Importantly, thermogravimetric...
The phase coexistence present through a first-order transition means there will be finite regions between the two phases where structure of system vary from one to other, known as boundary wall. This region is said play an important but unknown role in dynamics transitions. Here, by using both x-ray photon correlation spectroscopy and magnetometry techniques measure temporal isothermal development at various points thermally activated metamagnetic near-equiatomic FeRh alloy, we are able...
A novel valve-assisted pressure autoclave is described, facilitating 'snapshot' investigations of hydrothermal synthesis (HS) product suspensions rapidly quenched in liquid nitrogen. The approach gives near situ descriptions the HS reaction products, as characterised using transmission electron microscopy, and provides fundamental insight into mechanisms crystal growth. An investigation development α-Fe2O3 nanorods from aqueous FeCl3 solution clarifies role intermediate β-FeOOH nanorod...