A5076481271- Rare-earth and actinide compounds
- Magnetic Properties of Alloys
- Magnetic properties of thin films
- Magnetic Properties and Applications
- Iron-based superconductors research
- Magnetic and transport properties of perovskites and related materials
- Inorganic Chemistry and Materials
- Advanced Chemical Physics Studies
- Physics of Superconductivity and Magnetism
- Heusler alloys: electronic and magnetic properties
- Metallurgical and Alloy Processes
- High-pressure geophysics and materials
- Surface and Thin Film Phenomena
- Nuclear Materials and Properties
- Hydrogen Storage and Materials
- Boron and Carbon Nanomaterials Research
- Advanced Condensed Matter Physics
- Metallic Glasses and Amorphous Alloys
- nanoparticles nucleation surface interactions
- Catalytic Processes in Materials Science
- Metal and Thin Film Mechanics
- Advanced Materials Characterization Techniques
- Intermetallics and Advanced Alloy Properties
- Microstructure and Mechanical Properties of Steels
- Superconducting Materials and Applications
Polish Academy of Sciences
2016-2025
Institute of Molecular Physics of the Polish Academy of Sciences
2016-2025
Uppsala University
2014-2017
Włodzimierz Trzebiatowski Institute of Low Temperature and Structure Research
2015
Leibniz Institute for Solid State and Materials Research
2014
Poznań University of Technology
2007
Restrictions on the availability of rare earth metals create a strong demand for new rare-earth-free hard magnetic materials. In this study, we considered large set materials that are closely related to orthorhombic Fe3C (cementite) with aim characterizing trends in their intrinsic properties, highlighting relation between properties and chemical composition, identifying alloys optimal applications. A comprehensive analysis was conducted full concentration ranges hexagonal (ϵ) (θ) phases...
We have explored, computationally and experimentally, the magnetic properties of (${\mathrm{Fe}}_{1\ensuremath{-}x}{\mathrm{Co}}_{x}$)${}_{2}\mathrm{B}$ alloys. Calculations provide a good agreement with experiment in terms saturation magnetization magnetocrystalline anisotropy energy some difficulty describing ${\mathrm{Co}}_{2}\mathrm{B}$, for which it is found that both full potential effects electron correlations treated within dynamical mean field theory are importance correct...
We have analyzed by density functional theory calculations the structural and magnetic properties of Fe-Co alloys doped carbon. In analogy with formation martensite in steels we predict that such a structure also forms for wide range concentrations. These are predicted to stable tetragonal distortion, which turn leads an enhanced magnetocrystalline anisotropy energy up 0.75 MJ/m${}^{3}$ saturated magnetization field 1.9 T.
In order to convert the well-known Fe-Co-B alloy from a soft hard magnet, we propose tetragonal strain by interstitial boron. Density functional theory reveals that when B atoms occupy octahedral sites, bcc Fe-Co lattice is strained spontaneously. Such highly distorted predicted reach strong magnetocrystalline anisotropy which may compete with shape anisotropy. To probe this theoretical suggestion experimentally, epitaxial films are examined. A spontaneous up 5% distortion obtained for...
The ordered L1$_0$ FeNi phase (tetrataenite) is recently considered as a promising candidate for the rare-earth free permanent magnets applications. In this work we calculate several characteristics of FeNi, where most results come form fully relativistic full potential FPLO method with generalized gradient approximation (GGA). A special attention deserves summary magnetocrystalline anisotropy energies (MAE's), calculations constant $K_3$, and combined analysis Fermi surface...
Fe$_5$SiB$_2$ has been synthesized and magnetic measurements have carried out, revealing that M$_{\text{sat}}$ = 0.92 MA/m at T 300 K. The M vs curve shows a broad peak around 160 anisotropy constant, K$_1$, estimated K, is 0.25 MJ/m$^3$. Theoretical analysis of system out extended to the full range Fe$_5$Si$_{1-x}$P$_x$B$_2$, Fe$_5$P$_{1-x}$S$_x$B$_2$, (Fe$_{1-x}$Co$_x$)$_5$SiB$_2$ compositions. electronic band structures calculated using Full-Potential Local-Orbital Minimum-Basis Scheme...
Magnetic tunnel junctions with a magnetic layer perpendicular anisotropy are currently used in computer memories that do not require voltage sustaining. An example of layers ultrathin FeCo films on Au substrate. Here, we present an experimental and computational study Fe$_{0.75}$Co$_{0.25}$ thickness up to two nanometers. The investigated surrounded both sides by layers. In experiment, found polycrystalline below 0.74 nm (five atomic monolayers). We also measured strong surface contribution...
A magnetization study of a La2Co7 single crystal has obtained the following anisotropy constants: K1 = 1.4 MJ/m3 and K2 0.02 (at room temperature). The corresponding field is 6.7 T; an earlier report much higher value (17 T) not been confirmed. significant (10%) observed. Density-functional calculations are in qualitative agreement with new data.
Fe-Co alloys with induced tetragonal strain are promising materials for rare-earth-free permanent magnets. However, as ultrathin-film studies have shown, structures tend to a rapid relaxation toward cubic structure the thickness of deposited film increases. One main methods inducing stable in bulk material is interstitial doping small atoms, like B, C, or N. In this work, we present full configuration-space analysis density functional theory approach...
The Fe$_5$PB$_2$ compound offers tunable magnetic properties via the possibility of various combinations substitutions on Fe and P-sites. Here, we present a combined computational experimental study (Fe$_{1-x}$Co$_{x}$)$_5$PB$_2$. Computationally, are able to explore full concentration range, while real samples were only obtained for 0 <= x 0.7. calculated moments, Curie temperatures, magnetocrystalline anisotropy energies (MAEs) found decrease with increasing Co concentration. substitution...
The crystal structures and the physical (magnetic, electrical transport thermodynamic) properties of ternary compounds CeRhSi2 Ce2Rh3Si5 (orthorhombic CeNiSi2- U2Co3Si5-type structures, respectively) were studied over wide ranges temperature magnetic field strength. results revealed that both materials are valence fluctuating systems, in line with previous literature reports. Direct evidence for fluctuations was obtained by means Ce LIII-edge x-ray absorption spectroscopy 3d core-level...
While the performance of magnetic tunnel junctions based on metal/oxide interfaces is determined by hybridization, charge transfer, and properties at interface, there are currently only limited experimental techniques with sufficient spatial resolution to directly observe these effects simultaneously in real-space. In this letter, we demonstrate an method Electron Magnetic Circular Dichroism (EMCD) that will allow researchers map transitions valency real-space over interfacial cross-sections...
Ultrathin ${L1}_{0}\phantom{\rule{4pt}{0ex}}\mathrm{FePt}$ films with different $c$-axis orientations relative to the film plane are promising candidates for data storage materials. In this work, within framework of density functional theory, we calculated magnetic properties ultrathin (111) and (010) thicknesses ranging from 4 16 atomic monolayers (from about 0.8 3.5 nm). The highest average moments observed thinnest considered and, increasing thickness, values converge towards moment bulk....
Single-crystalline ${\text{CeRh}}_{3}{\text{Si}}_{2}$ was investigated by means of x-ray diffraction, magnetic susceptibility, magnetization, electrical resistivity, and specific-heat measurements carried out in wide temperature field ranges. Moreover, the electronic structure compound studied at room cerium core-level photoemission spectroscopy (XPS). The physical properties were analyzed terms crystalline electric compared with results ab initio band-structure calculations performed within...
Intermetallic YCo2 compound is a Pauli exchange-enhanced paramagnet. Structural and magnetic properties melt-spun pure alloyed with Nb or Ti are presented. The samples crystallize in MgCu2-type phase lattice constant changing from 7.223 Å for YCo2, through 7.213 Y0.9Nb0.1Co2 to 7.192 Y0.9Ti0.1Co2, where Y atoms replaced by atoms. Nanocrystalline phases can be produced appropriate cooling rates the solidification process. By synthesis process free volumes, vacancies, introduced into...
Abstract Ostwald ripening is a well‐known physicochemical phenomenon in which smaller particles, characterized by high surface energy, dissolve and feed the bigger ones that are thermodynamically more stable. The effect commonly observed solid liquid solutions, as well systems consisting of supported metal clusters or droplets. Here, evidence provided for occurrence an oxide‐on‐metal system which, this case, consists ultrathin iron monoxide (FeO) islands grown on Ru(0001) single‐crystal...
The magnetic properties of the compound ${\mathrm{Fe}}_{5}{\mathrm{Si}}_{1\ensuremath{-}x}{\mathrm{P}}_{x}{\mathrm{B}}_{2}$ have been studied, with a focus on Curie temperature ${T}_{\mathrm{C}}$, saturation magnetization ${M}_{\mathrm{S}}$, and magnetocrystalline anisotropy. Field dependent measurements were used to determine ${T}_{\mathrm{C}}\left(x\right)$ ${M}_{\mathrm{S}}\left(x\right)$. at 10 K (300 K) is found monotonically decrease from...
The substitutional effects of cobalt in (Fe1-xCox)5PB2 have been studied with respect to crystalline structure and chemical order X-ray diffraction Mössbauer spectroscopy. magnetic properties determined from measurements, density functional theory calculations performed for the both end compounds, as well chemically disordered intermediate compounds. crystal is tetragonal (space group I4/mcm) two different metal sites, a preference atoms M(2) position (4c) at higher contents. substitution...