scholarly journals Verteilung und Valenz der Kationen in Spinellsystemen mit Eisen und Vanadium, VIII / Distribution and Valence of the Cations in Spinel Systems with Iron and Vanadium, VIII

1989 ◽  
Vol 44 (11) ◽  
pp. 1427-1437 ◽  
Author(s):  
Erwin Riedel ◽  
Jörg Kähler ◽  
Norbert Pfeil
Keyword(s):  
Magnetic Field ◽  
Magnetic Interaction ◽  
Iron Ion ◽  
Iron Species ◽  
Lattice Constants ◽  
Seebeck Coefficients ◽  
Octahedral Sites ◽  
Charge Hopping ◽  
Mössbauer Data ◽  
Conduction Electron Density

From lattice constants and Mössbauer data the valence distribution and an energy-level diagram of the spinel system Fe(FexV2-x)O4 have been derived. In the range 0.3 ≦ χ ≦ 1.5 the transition from normal to inverse spinels takes place. The Mößbauer spectra with 1.0 ≦ χ ≦ 2.0 consist of two sets of sextets corresponding to tetrahedral and octahedral sites. Typical values of isomer shift and internal magnetic field strength due to the different environments of the iron ion result from the superimposed sextets of the octahedral site pattern. Neighbouring V ions enhance the conduction electron density and diminish the strength of the magnetic interaction. Mößbauer data, Seebeck coefficients and activation energies lead to a model of both tetrahedral and octahedral conduction based on charge hopping. For Fe1,9V1,1 O4 there exists only one iron species.

Verteilung und Valenz der Kationen in Spinellsystemen mit Eisen und Vanadium, VI Gitterkonstanten, Mößbauer-Spektren und elektronische Eigenschaften der Mischkristallreihe ZnFeVO4—Fe2VO4 / Distribution and Valence of the Cations in Spinel Systems with Iron and Vanadium, VI Lattice Constants, Mössbauer Spectra and Electronic Properties of the Solid Solution ZnFeVO4—Fe2VO4

1989 ◽  
Vol 44 (8) ◽  
pp. 869-874 ◽  
Author(s):  
Erwin Riedel ◽  
Angela Ostermann ◽  
Jörg Kähler
Keyword(s):  
Solid Solution ◽  
Cation Distribution ◽  
Room Temperature ◽  
Mössbauer Spectra ◽  
Iron Species ◽  
Lattice Constants ◽  
Mossbauer Spectra ◽  
Seebeck Coefficients ◽  
Charge Hopping ◽  
Mössbauer Data

The cation distribution and an energy level diagram of the spinel system ZnFeVO4—Fe2VO4 have been calculated from the lattice constants. The results are in agreement with the Mössbauer spectra. Mössbauer data, Seebeck coefficients and activation energies lead to a model of both tetrahedral and octahedral conduction based on charge hopping. For Zn0.4Fe 1.6VO4 there exists only one iron species. Fe2VO4 has at room temperature the cation distribution Fe0.42+Fe0.63+(Fe0.62+Fe0.43+V3+)O4

scholarly journals Verteilung und Valenz der Kationen in Spinellsystemen mit Eisen und Vanadium, IIRöntgenographische Untersuchung, Seebeck Koeffizienten, Mößbauer-und IR-Spektren der Mischkristallreihen Fe2VO4-ZnV2O4 und Fe2VO4-ZnFe2O4 / Distribution and Valence of the Cations in Spinel Systems with Iron and Vanadium, IIX-ray Investigation, Seebeck Coefficients, Mössbauer and IR Spectra of the Solid Solutions Fe2VO4-ZnV2O4 and Fe2VO4-ZnFe2O4

1980 ◽  
Vol 35 (10) ◽  
pp. 1261-1267 ◽  
Author(s):  
Erwin Riedel ◽  
Norbert Pfeil
Keyword(s):  
Ir Spectra ◽  
Solid Solutions ◽  
Mössbauer Spectra ◽  
Tetrahedral Site ◽  
Seebeck Effect ◽  
Inverse Spinel ◽  
Lattice Constants ◽  
Mossbauer Spectra ◽  
Seebeck Coefficients ◽  
Charge Hopping

Abstract The spinel series Fe2VO4-ZnV2O4 and Fe2VO4-ZnFe2O4 have been prepared and investigated. The lattice constants and Mössbauer spectra lead to a distribution of cations which proves that Fe2VO4 is a partially inverse spinel with Fe(II) and Fe(III) on the tetrahedral site. The Seebeck effect is interpreted with a model of both tetrahedral and octahedral conduction based on charge hopping.

Modelling and experimental characterisation of a compressional adaptive magnetorheological elastomer isolator

2021 ◽  
pp. 107754632110253
Author(s):  
Emiliano Rustighi ◽  
Diego F Ledezma-Ramirez ◽  
Pablo E Tapia-Gonzalez ◽  
Neil Ferguson ◽  
Azrul Zakaria
Keyword(s):  
Magnetic Field ◽  
Silicone Rubber ◽  
Magnetic Interaction ◽  
Iron Particle ◽  
Material Model ◽  
Rubber Matrix ◽  
Magnetorheological Elastomer ◽  
Volume Percentage ◽  
Shock Absorbers ◽  
Percent Concentration

This article proposes a simple physical-based model to describe and predict the performance of axially compressed magnetorheological elastomer cylinders used as vibration and shock absorbers. The model describes the magnetorheological elastomer macroscopic stiffness changes because of an externally applied magnetic field from a microscopic composite cell of silicone rubber and carbonyl iron particle. Despite neglecting the material hyperelasticity, anisotropy and adjacent magnetic interaction, the model describes effectively the effect of the magnetic field on the macroscopic modulus of elasticity. The changes in the mechanical properties with the induced magnetic field are measured on samples of different particle concentration based on volume percentage, that is, 10 and 30 percent concentration of iron particles in a silicone rubber matrix. The manufacturing process of the samples is detailed, as well as the experimental validation of the effective stiffness change under a magnetic field in terms of transmissibility and mobility testing. However, the prediction seems to be limited by the linear elastic material model. Predictions and measurements are compared, showing that the model is capable of predicting the tunability of the dynamic/shock absorber and that the proposed devices have a possible application in the reduction of mechanical vibrations.

scholarly journals Reorientation of α-Fe2O3crystallites in an external magnetic field

2014 ◽  
Vol 70 (a1) ◽  
pp. C165-C165
Author(s):  
Michał Stękiel ◽  
Radosław Przeniosło ◽  
Dariusz Wardecki ◽  
Thomas Buslaps ◽  
Jacek Jasiński
Keyword(s):  
Magnetic Field ◽  
Angular Distribution ◽  
External Field ◽  
Intensity Distribution ◽  
Azimuthal Angle ◽  
Magnetic Interaction ◽  
Cylindrical Container ◽  
Ambient Conditions ◽  
X Ray ◽  
Weak Ferromagnetic

The magnetic interaction between the crystallites of weak ferromagnetic α-Fe2O3 has been studied by combining SR based X-ray diffraction with an externally applied magnetic field. The measurements were performed with several polycrystalline α-Fe2O3 [1,2] samples (dry or in suspensions) placed in a half-filled cylindrical container in ambient conditions. The axis of the cylindrical container was oriented vertically parallel to the applied dc magnetic field. The polycrystalline sample had a free surface, so the α-Fe2O3 crystallites were free to move. The full Debye-Scherrer diffraction rings were measured with a 2D pixel detector at the beamline ID-15B at ESRF. In the absence of the magnetic field the intensity distribution over azimuthal angle was a uniform, i.e. there was no texture. The applied maximal field, B=0.9T was too small to change the magnetic ordering of α-Fe2O3 but it was sufficiently strong to reorient large amount of crystallites in order to minimize the angle between their ferromagnetic moment direction and the external field. Pronounced texture patterns with clear maxima in the angular distribution of the intensity across each Debye-Scherrer ring were observed. The observed textured intensity distribution was analyzed quantitatively by using a model based on the magnetic anisotropy observed in single crystals of α-Fe2O3. The analysis yielded two important parameters: (i) the width of the angular distribution of the ferromagnetic moments directions around the external field direction, and (ii) the relative quantity of the crystallites that did reorient in the external field. The α-Fe2O3 samples were also characterized with TEM technique. The analysis of X-ray and TEM studies provide new conclusions about the magnetic interaction between the α-Fe2O3 crystallites [3]. The proposed measurement technique can be applied to study other weak ferromagnetic materials.

Rotating 1-D magnetic photonic crystal balls with a tunable lattice constant

Nanoscale ◽  
2017 ◽  
Vol 9 (27) ◽  
pp. 9548-9555 ◽  
Author(s):  
Wei Luo ◽  
Jindan Yan ◽  
Yali Tan ◽  
Huiru Ma ◽  
Jianguo Guan
Keyword(s):  
Magnetic Field ◽  
Photonic Crystal ◽  
Lattice Constant ◽  
Lattice Constants ◽  
Magnetic Photonic Crystal

1-D magnetic photonic crystal balls with uniform colors can be smoothly rotated by magnetic field even when the lattice constants change with stimuli.

scholarly journals Clarification of the Magnetocapacitance Mechanism for Fe3O4-PDMS Nanocomposites

2015 ◽  
Vol 2015 ◽  
pp. 1-6 ◽  
Author(s):  
Chen Guobin ◽  
Yang Hui ◽  
Zhang Xiaoming ◽  
Liu Jun ◽  
Tang Jun
Keyword(s):  
Magnetic Field ◽  
Magnetic Properties ◽  
Magnetic Property ◽  
Preparation Method ◽  
Volume Fraction ◽  
Magnetic Interaction ◽  
Mechanical Parameters ◽  
Measurement Results

We mainly focused on the magnetocapacitance effect of Fe3O4-PDMS nanocomposites. We also proposed the preparation method and measured microstructures, magnetic properties, and magnetocapacitance value of the nanocomposites. The magnetocapacitance measurement results show that the nanocomposites have magnetocapacitance property, the magnetocapacitance with magnetic field depends on the magnetic property, and the value at the same magnetic field is increasing with the volume fraction of Fe3O4nanoparticles. The magnetocapacitance model is proposed to explain this phenomenon by analyzing the magnetic interaction between particles and the viscoelasticity of PDMS. We also calculated the theoretical capacitance value of all samples using the magnetization of nanoparticles and mechanical parameters of PDMS. From the theoretical values, it is concluded that the model we proposed can well explain the magnetocapacitance effect of Fe3O4-PDMS nanocomposites.

Optical and Magnetic Properties of Silica Implanted with N+ and Fe+

1995 ◽  
Vol 396 ◽  
Author(s):  
T. Isobe ◽  
R.A. Weeks ◽  
R.A. Zuhr
Keyword(s):  
Magnetic Field ◽  
Relative Intensity ◽  
Chemical Interaction ◽  
Resonance Field ◽  
Magnetic Interaction ◽  
Atomic Ratio ◽  
Resonance Absorption ◽  
Iron Nitrides ◽  
Optical And Magnetic Properties ◽  
Different Doses

AbstractSilica platelets (Corning 7940) were implanted sequentially with N at 52 keV to different doses ranging from 0 to 1.2×l017 ions cm2 and then with Fe at 160 keV to a dose of 6×10 ions cm2. The optical absorption decreased with increasing N1 dose at photon energies ranging from 1.4 eV to 6.5 eV. The relative intensity, S(0°), of the ferromagnetic resonance absorption and its resonance field, H(0°), at θ = 0° were larger than S(90°) and H,(90°) at 0 = 90°, where Θ is the angle between the applied magnetic field and the normal to the implanted surface. The maximum values of S(0°) and S(90°) were observed near the N/Fe atomic ratio of 0.2. At the similar atomic ratio, the differential relative intensity, S(0°)- S(90°), and the differential resonance field, H,(0°)-H,(90°). associated with the degree of magnetic interaction between the produced compounds, also showed maxima. We conclude that sequential ion-implantation of N1 and Fe1 into silica causes a chemical interaction to produce iron nitrides.

scholarly journals Martensitic transformation in the systems based on Fe-Ni compositions in strong pulsed magnetic fields

2021 ◽  
pp. 22-29 ◽  
Author(s):  
I. Zolotarevskii
Keyword(s):  
Magnetic Field ◽  
Martensitic Transformation ◽  
Magnetic Fields ◽  
Temperature Dependence ◽  
Strong Magnetic Field ◽  
Low Temperatures ◽  
Strong Dependence ◽  
Magnetic Interaction ◽  
Iron Alloys ◽  
Pulsed Magnetic Fields

Purpose of work. To ascertain the causes of the abnormally large displacement of the martensitic point in steels and iron alloys in strong pulsed magnetic fields at low temperatures. Research methods. Generalization of experimental and theoretical investigations of the strong magnetic field influence on the martensitic transformation in steels and iron alloys, taking into account the magnetic state of austenite. The obtained results. The distributions of the martensitic point displacement ΔMS from the content of the main component - iron and the temperature of the martensitic γ → α- transformation beginning (martensitic point MS) in different experiments are obtained. It is shown that the obtained temperature dependence ΔMS(MS) in a strong magnetic field at low temperatures decomposes into two components, one of which correlates with the generalized Clapeyron-Clausius equations, and the other is opposite to it. In addition, it was found that steels and alloys with intense γ → α- transformation in a magnetic field contain at least 72.5% iron (wt), which at low temperatures in the fcc structure is antiferromagnetic. Scientific novelty. The anomalous temperature dependence of the distribution ΔMS(MS) in a strong magnetic field is explained on the basis of quantum representations of the magnetic interaction of atoms in the Fe-Ni system. This effect is associated with a number of other invar effects, in particular, with an abnormally large spontaneous and forced magnetostriction, a strong dependence of the resulting exchange integral on the interatomic distance. The point of view according to which in these alloys in a magnetic field γ → α- transformation occurs by the type of “magnetic first kind phase transformation” is substantiated. It is assumed that the nucleation of the martensitic phase in a magnetic field occurs in (at) local regions of γ- phase with disoriented atomic magnetic moments (with high compression and increased forced magnetostriction). Practical value. The information obtained in this work provides grounds for explaining the kinetic features of the transformation of austenite into martensite in steels and iron alloys.

Effects of the Applied Magnetic Field and Magnetic Interaction on the Magnetic Switching Volume in CoSm Films

2010 ◽  
Vol 60 (12) ◽  
pp. 1288-1293
Author(s):  
Sang In KIM ◽  
Jong Duk LEE ◽  
Hyeon Soo KIM ◽  
Soon Young JEONG*
Keyword(s):  
Magnetic Field ◽  
Applied Magnetic Field ◽  
Magnetic Interaction ◽  
Magnetic Switching

scholarly journals Magnetic Domain Transition of Adjacent Narrow Thin Film Strips with Inclined Uniaxial Magnetic Anisotropy

Micromachines ◽  
2020 ◽  
Vol 11 (3) ◽  
pp. 279
Author(s):  
Tomoo Nakai
Keyword(s):  
Magnetic Field ◽  
Easy Axis ◽  
Magnetic Domain ◽  
Magnetic Interaction ◽  
Individual Element ◽  
Typical Characteristic ◽  
Many Body ◽  
Uniaxial Magnetic Anisotropy ◽  
Line Arrangement ◽  
Normal Magnetic Field

This study deals a phenomenon of magnetic domain transition for the stepped magneto-impedance element. Our previous research shows that an element with 70° inclined easy axis has a typical characteristic of the domain transition, and the transition can be controlled by the normal magnetic field. In this paper, we apply this phenomenon and controlling method to the line arrangement adjacent to many body elements, in which mutual magnetic interaction exists. The result shows that the hidden inclined Landau–Lifshitz domain appears by applying a distributed normal field the same as an individual element.

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