A5102997052- Magnetic properties of thin films
- Theoretical and Computational Physics
- Physics of Superconductivity and Magnetism
- Magnetic Properties and Applications
- Magnetic and transport properties of perovskites and related materials
- Force Microscopy Techniques and Applications
- Metallic Glasses and Amorphous Alloys
- Characterization and Applications of Magnetic Nanoparticles
- ZnO doping and properties
- Advanced Memory and Neural Computing
- Geomagnetism and Paleomagnetism Studies
- Thermography and Photoacoustic Techniques
- Magnetic Properties of Alloys
- Ion-surface interactions and analysis
- Electronic and Structural Properties of Oxides
- Nanoparticle-Based Drug Delivery
- Multiferroics and related materials
- Thermal properties of materials
- Advanced Condensed Matter Physics
- Geophysical and Geoelectrical Methods
- Ferroelectric and Negative Capacitance Devices
- Near-Field Optical Microscopy
- Advancements in Photolithography Techniques
- Magnetic Properties and Synthesis of Ferrites
- Quantum and electron transport phenomena
National Physical Laboratory
2018-2024
University of Manchester
2011-2022
Craig Technologies (United States)
2020
Lanzhou University
2018
King Abdullah University of Science and Technology
2018
Lehman College
2018
City University of New York
2018
Chinese Academy of Sciences
2018
Leibniz Institute for Solid State and Materials Research
2018
Institute of Physics
2018
Since it was first demonstrated in 1987, magnetic force microscopy (MFM) has become a truly widespread and commonly used characterization technique that been applied to variety of research industrial applications. Some the main advantages method includes its high spatial resolution (typically ∼50 nm), ability work variable temperature fields, versatility, simplicity operation, all without almost any need for sample preparation. However, most commercial systems, historically provided only...
Magnetic skyrmions are topologically protected nanoscale spin textures exhibiting fascinating physical behaviors. Recent observations of room temperature in sputtered multilayer films an important step towards their use ultra-low power devices. Such practical applications prefer to be stable at zero magnetic fields and temperature. Here, we report the creation skyrmion lattices Pt/Co/Ta multilayers by a scanning local field using force microscopy tips. We also show that those newly created...
Magnetic skyrmions are topologically non-trivial nanoscale objects. Their topology, which originates in their chiral domain wall winding, governs unique response to a motion-inducing force. When subjected an electrical current, the winding of spin texture leads deflection skyrmion trajectory, characterized by angle with respect applied force direction. This Hall was believed be diameter-dependent. In contrast, our experimental study finds that within plastic flow regime is...
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 Equi-atomic FeRh is highly unusual in that it undergoes a first order meta-magnetic phase transition from an antiferromagnet to ferromagnet above room temperature ( T r ≈ 370 K). This behavior opens new possibilities for creating multifunctional magnetic and spintronic devices which can utilise both thermal applied field energy change state functionalise composites. A key requirement realising the need understand control properties of extreme thin film limit t < 10 nm) where...
We experimentally study the thermoelectrical signature of individual skyrmions in chiral $\mathrm{Pt}/\mathrm{Co}/\mathrm{Ru}$ multilayers. Using a combination controlled nucleation, single skyrmion annihilation, and magnetic field dependent measurements thermoelectric is characterized. The observed explained by anomalous Nernst effect skyrmion's spin structure. Possible topological contributions to are discussed. Such characterization allows for noninvasive detection counting enables...
The future of consumer electronics depends on the capability to reliably fabricate nanostructures with given physical properties. Therefore, techniques characterize materials and devices nanoscale resolution are crucial. Among these is magnetic force microscopy (MFM), which transduces between sample a oscillating probe into phase shift, enabling locally resolved study field patterns down 10 nm. Here, progress done toward making quantitative MFM common tool in nanocharacterization...
This Roadmap provides an overview of the critical role materials in exploiting spin and topology for next-generation quantum technologies including computing, sensing, information storage networking devices. We explore key systems that support topological phenomena discuss their figures merit. Spin topology-based have several advantages over classical, charged-based counterparts, non-volatility, faster data processing speeds, higher integration densities lower power consumption. main...
FeRh and its first-order phase transition can open new routes for magnetic hybrid materials devices under the assumption that it be exploited in ultra-thin-film structures. Motivated by experimental measurements showing an unexpected increase temperature with decreasing thickness of on top MgO, we develop a computational model to investigate strain effects such Our theoretical results show presence MgO interface changes configuration which drives anomalous behavior.
Magnetic force microscopy (MFM) can be considered as a standard tool for nano-scale investigation of magnetic domain structures by probing the local stray field landscape measured sample. However, this generally provides only qualitative data. To quantify fields, MFM system must calibrated. that end, transfer function (TF) approach was proposed, that, unlike point probe models, fully considers finite extent tip. albeit being comprehensive, TF is not yet well established, mainly due to...
We show a method to control magnetic interfacial effects in multilayers with Dzyaloshinskii-Moriya interaction (DMI) using helium (He[Formula: see text]) ion irradiation. report results from SQUID magnetometry, ferromagnetic resonance as well Brillouin light scattering on DMI function of irradiation fluence study the effect properties multilayers. Our clear evidence He[Formula: text] which is consistent interface modification due This external degree freedom offers promising perspectives...
Abstract The equiatomic alloy FeRh is of great scientific and technological interest due its highly unusual first-order antiferromagnetic (AF) to ferromagnetic (FM) phase transition. Here we report an exploration the interplay between topography evolution with a comprehensive magnetic force microscopy study nominal 50 nm thick thin films subtractively patterned wires width 0.2 µm–2 µm. In continuous where surface morphology had not been optimised for smoothness, topographical variation was...
The first order antiferromagnetic to ferromagnetic metamagnetic phase transition of equiatomic FeRh offers new opportunities for novel memories and spintronic devices with the caveat that it can be utilized in thin film structures (&lt;50 nm). Here, we report a polarized neutron reflectivity (PNR) study three representative thicknesses (5, 20, 50 nm) aimed at determining physical magnetic structure room temperature partway through transition. PNR results are analyzed reference X-ray...
We demonstrate the control of perpendicular magnetic anisotropy (PMA) in multilayer films without modification either microstructure or saturation magnetization by tuning Ar+ ion energy using remote plasma sputtering. show that for [Co/Pd]8 films, increasing results a strong decrease PMA through an increase interfacial roughness determined X-ray reflectivity measurements. diffraction and transmission electron microscope image data is independent energy. This opens different approach to...
We report on the depth-sensitive, temperature-dependent exchange coupling in an FePt/FeRh thin-film exchange-spring structure. The depth-dependent in-plane magnetization is measured as a function of applied magnetic field and sample temperature using polarized neutron reflectometry (PNR). profiles are interpreted terms competition between anisotropy, coupling, dipolar FeRh undergoes phase transition from antiferromagnetic to ferromagnetic ordering. PNR data combined with bulk magnetometry...
We present the results of an experiment to locally resolve spin Seebeck effect in a high-quality yttrium iron garnet--Pt sample. achieve this by using heated scanning thermal probe generate highly local nonequilibrium current. To support our experimental results, we also model based on thermodynamic approach that is good agreement with findings. further corroborate index resolved magnetization texture magnetic force microscopy and correlate corresponding regions. hypothesize technique allows...
The interfacing of magnetic materials with nonmagnetic heavy metals a large spin-orbit coupling, such as $\mathrm{Pt}$, results in an asymmetric exchange interaction at the interface due to Dzyaloshinskii-Moriya (DMI), which turn leads formation skyrmions and topological spin structures perpendicularly magnetized multilayers. Here, we show that out-of-plane domains lateral dimensions from 200 nm 2 $\ensuremath{\mu}\mathrm{m}$ are stabilized in-plane $\mathrm{Ta}$/$\mathrm{Co}$/$\mathrm{Pt}$...
Bit-patterned media recording (BPMR) is a magnetic data storage solution where the medium patterned into nanoscale islands, each representing one bit of data. Write errors can occur in BPMR, especially islands have position, shape, or properties that are very different from mean, i.e., those tails any parameter probability density functions (PDFs). We used model BPMR incorporates variable shape PDFs to study write errors. This shows precise distributions critical determining error...
Spatially resolved thermoelectric detection of magnetic systems provides a unique platform for the investigation spintronic and spin caloritronic effects. Hitherto, these investigations have been resolution-limited, confining analysis response to regions where magnetization is uniform or collinear at length scales comparable domain size. Here, we investigate from single trapped wall using heated scanning probe. Following this approach, unambiguously resolve due its local response. Combining...
In synthetic antiferromagnets (SAFs) the combination of antiferromagnetic order and synthesis using conventional sputtering techniques is combined to produce systems that are advantageous for spintronics applications. Here we present preparation study SAF multilayers possessing both perpendicular magnetic anisotropy Dzyaloshinskii-Moriya interaction kind used as hosts chiral spin textures. The have an antiferromagnetically (AF) aligned ground state but can be forced into a full ferromagnetic...
Lowering the temperature at which desirable L10 phase forms in FePt thin films is a key requirement development of next generation high-density data storage media and spintronic devices. Remote plasma sputtering offers higher degree control over parameters, allowing properties to be tailored, potentially can affect ordering kinetics FePt. Here, we report comprehensive study deposited under range temperatures conditions. X-ray diffraction magnetometry investigations show that whilst ordered...
A nanopatterning method involving a ferromagnetic (FM)–paramagnetic (PM) phase transformation caused by ion irradiation has been developed. (Fe0.56Mn0.44)50Pt50 film with the ordered L10 structure and uniaxial magnetocrystalline anisotropy constant (Ku) of 2.1 × 106 J m− 3 was fabricated. Mn produced smooth FM dot array diameters 100 nm surrounded PM phase, which obtained from induced FM–PM transition structural to disordered A1 slight increase in content. The magnetization reversal process...
Fe${}_{50}$Rh${}_{50}$ is an unusual alloy with a first-order metamagnetic phase transition above room temperature. Thin-film structures of FeRh engineered interfacial exchange interactions are multifunctional, responding to temperature, magnetic field, and strain. The authors use experiments simulations study reduced switching fields in both macroscale Fe-Pt/FeRh thin films mesoscale islands, allowing the constants between layers be determined. This will promote development nanoscale,...