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.

Chemical interaction between nitrogen and iron in silica glasses via sequential ion-implantation

1998 ◽  
Vol 13 (8) ◽  
pp. 2144-2150
Author(s):  
Tetsuhiko Isobe ◽  
Tamotsu Toriyama ◽  
Robert A. Weeks ◽  
Raymond A. Zuhr
Keyword(s):  
Ion Implantation ◽  
Chemical Interaction ◽  
Atomic Ratio ◽  
Photoelectron Spectra ◽  
Iron Nitride ◽  
X Ray ◽  
Silica Glasses ◽  
N Dose ◽  
Two Peaks ◽  
Different Doses

Silica glass plates (Corning 7940 excimer grade) were implanted sequentially with N+ at 52 keV to different doses, ranging from 0 to 1.2 × 1017 ions cm−2, and then with Fe+ at 160 keV to 6 × 1016 ions cm−2 at room temperature and 4 µA cm−2. The intensity of ferromagnetic magnetic resonance (FMR) absorption and the magnetization calculated by the angular dependence of the FMR field reach maxima at an N/Fe atomic ratio ∼0.2. Two peaks due to Fe 2p3/2 electron are observed at 707.2 ± 0.2 and 710.9 ± 0.2 eV in the x-ray photoelectron spectra. The intensity of the former relative to the latter decreases with increasing the N dose. The conversion electron Mössbauer spectrum reveals the formation of superparamagnetic iron nitride as well as the existence of Fe2+ and Fe3+ in silica when implanting N+ to 7.5 × 1015 ions cm−2 and then Fe+ to 6 × 1016 ions cm−2 at N/Fe = 0.125. These results suggest that sequential ion-implantation of N+ and Fe+ produces iron nitride in silica glasses.

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.

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.

Light-induced reversible ionization of tetramethylphenylenediamine in an inorganic polymer of n-butyl orthotitanate

1988 ◽  
Vol 66 (8) ◽  
pp. 1931-1935
Author(s):  
Hisashi Ueda ◽  
Masahiro Kaise
Keyword(s):  
Relaxation Time ◽  
Electron Spin Resonance ◽  
Visible Light ◽  
Relative Intensity ◽  
Hyperfine Splitting ◽  
Resonance Absorption ◽  
Spin Quantum ◽  
Spin Quantum Number ◽  
Spin Resonance ◽  
Intensity Ratios

n-Butyl orthotitanate, BT, polymerized in tetrahydrofuran, if irradiated by visible light, gives a new electron spin resonance absorption that is not found before irradiation. In the present work, three different polymers of BT were synthesized by adding tetramethyl phenylenediamine (TMPD), dimethyl phenylenediamine (DMPD), or phenylenediamine (PD), to the solution of BT. The polymers thus prepared were tested to see if they give a new esr signal when irradiated by visible light. The polymer to which 1 mol% of TMPD was added gave TMPD•+ when irradiated by visible light, but the TMPD•+ signal decayed after the irradiation was discontinued. This change, therefore, is reversible. The resonant position of every hyperfine splitting line of the TMPD•+ found in this polymer coincided with that of TMPD•+ in solution, but the relative intensity ratios and the line width of each line depended on the nuclear spin quantum number of the coupling nuclei. This can be interpreted by the restricted rotational motion of TMPD•+ in the polymer matrix. The contribution of the non-diagonal term to the spin relaxation time would explain this phenomenon. In the case of the polymer to which DMPD was added, a small amount of DMPD•+ seemed to be formed, but no radical was detected in the case of the polymer to which PD was added.

Exchange Bias Induced in Polycrystalline Co/FeMn-Structures by Magnetic Field Cooling

2012 ◽  
Vol 190 ◽  
pp. 81-84
Author(s):  
N.G. Chechenin ◽  
I.O. Dzhun ◽  
S.A. Dushenko ◽  
E.A. Konstantinova
Keyword(s):  
Magnetic Field ◽  
Exchange Bias ◽  
Resonance Field ◽  
Bias Effect ◽  
Exchange Bias Effect ◽  
Annealing Temperatures ◽  
Layer Deposition ◽  
High Annealing ◽  
Thin Interlayer ◽  
Anneal Temperature

Using the method of angular dependence of ferromagnetic resonance field the magnetic properties of Si/SiO2/Cu/Co/FeMn/Cu and Si/SiO2/Cu/Co/Cu/FeMn/Cu structures were investigated. The layer deposition was carried out by magnetron sputtering in absence of an external magnetic field. It was established that thermal annealing with further cooling down in presence of a magnetic field can generate an exchange bias at anneal temperature significantly below the bulk antiferromagnetic Néel temperature. It was also shown that a thin interlayer between ferromagnetic and antiferromagnetic layers reduces the exchange bias effect at low anneal temperatures, however, makes this effect more stable at high annealing temperatures.

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.

scholarly journals X-Ray Flares and Outflows Driven by Magnetic Interaction Between a Protostar and its Surrounding Disk

1997 ◽  
Vol 163 ◽  
pp. 717-718
Author(s):  
Mitsuru Hayashi ◽  
Kazunari Shibata ◽  
Ryoji Matsumoto
Keyword(s):  
Magnetic Field ◽  
Current Sheet ◽  
Plasma Temperature ◽  
Magnetic Interaction ◽  
Central Star ◽  
X Ray ◽  
Mhd Simulations ◽  
Flare Loops ◽  
Hot Plasma ◽  
Dipole Magnetic Field

AbstractHere we present a model of hard X-ray flares and hot plasma outflows (optical jets) observed in protostars. Assuming that the dipole magnetic field of a protostar threads the protostellar disk, we carried out 2.5-dimensional magnetohydrodynamic (MHD) simulations of the diskstar interaction. The closed magnetic loops connecting the central star and the disk are twisted by the rotation of the disk. In the presence of resistivity, magnetic reconnection takes place in the current sheet formed inside the expanding loops. Hot, outgoing plasmoid and post flare loops are formed as a result of the reconnection. Numerical results are consistent with the observed plasma temperature (107 – 108K), the length of the flaring loop (1011 – 1012cm), and the speed of optical jets (200 – 400 km s−1 ).

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