Magnetic Anisotropy of Co-Nanostructures Embedded in Matrices with Different Pores Size and Morphology

2015 ◽  
Vol 233-234 ◽  
pp. 583-586 ◽  
Author(s):  
Elena Denisova ◽  
Lidia Chekanova ◽  
Rauf Iskhakov ◽  
Sergey Komogortsev ◽  
Ivan Nemtsev ◽  
...  
Keyword(s):  
Composite Materials ◽  
Magnetic Anisotropy ◽  
Anisotropy Field ◽  
X Ray Diffraction ◽  
Local Anisotropy ◽  
Polycarbonate Membrane ◽  
Crystalline Anisotropy ◽  
P Content ◽  
Polycarbonate Membranes ◽  
Size And Morphology

Composite materials with Co (P) particles embedded into pores of silica and track etched polycarbonate membranes were fabricated by an electroless reduction. The magnetic and structural properties of the composite materials are characterized by scanning electron microscopy, X-ray diffraction, and vibrating sample magnetometer. The macroscopic and local magnetic anisotropy of the Co (P) particles electroless deposited in the pores of the polycarbonate membrane and silica is studied. The composite materials with linear pores exhibit uniaxial magnetic anisotropy. The easy axis lies along the Co (P) rods, the shape anisotropy dominates over the intrinsic crystalline anisotropy. Information on local anisotropy field and the grain size was obtained from investigation of approach to saturation magnetization law. The local anisotropy field for all the samples depends on P content. For Co (P) rods the local anisotropy value is also determined by nominal pore sizes. It was found that the investigated Co (P) rods is nanocrystalline. The effects of different pores morphology on the FMR-spectra characteristics are studied.

Micromagnetic Simulation on the Microwave Magnetic Properties of Glass-Coated Amorphous Alloy Microwires

2013 ◽  
Vol 668 ◽  
pp. 733-736
Author(s):  
Yong Jiang Di ◽  
Peng Jun Cao ◽  
Bi Jia ◽  
Jian Jun Jiang
Keyword(s):  
Finite Element Method ◽  
Magnetic Anisotropy ◽  
Magnetic Domain ◽  
Anisotropy Field ◽  
Magnetic Alloy ◽  
Microwave Resonance ◽  
Crystalline Anisotropy ◽  
Magnetic Spectrum ◽  
Simulation Results ◽  
Magneto Crystalline Anisotropy

The magnetic structure of the glass-coated magnetic alloy microwires were modeled based on the main magnetic domain structure and meshed by finite element method. The magnetic spectrum of the magnetic alloy microwires was calculated based on the micromagnetic theory. The simulation results of the magnetic spectrum of glass-coated magnetic alloy microwires showed that the magnetic anisotropy field increase as the magneto-crystalline anisotropy constants increase. The microwave resonance frequency increased accompanied by the reduction of the permeability and the increase of the magnetic anisotropy field of the glass-coated magnetic alloy microwires.

Components of Magnetic Anisotropy of Soft Magnetic Nanocrystalline Fe-Based Films

2015 ◽  
Vol 233-234 ◽  
pp. 619-622 ◽  
Author(s):  
E.V. Harin ◽  
Elena N. Sheftel
Keyword(s):  
Magnetron Sputtering ◽  
Magnetic Anisotropy ◽  
Hysteresis Loops ◽  
Anisotropy Field ◽  
The Other ◽  
Structure Parameters ◽  
Soft Magnetic ◽  
Local Anisotropy ◽  
Magnetoelastic Anisotropy ◽  
Residual Macrostresses

We present quantitative evaluation results of micromagnetic structure parameters of nanocrystalline Fe, Fe95Zr5, Fe90N10, and Fe85Zr5N10films obtained by magnetron sputtering. It is shown that quantities of magnetocrystallineK1, magnetoelasticKME, magnetostaticKMS, and surfaceKa,Sanisotropies are components of experimentally measured effective local anisotropyKeff. The shape of the hysteresis loops of the films is determined by the presence of two main macroscopic effective magnetic anisotropies, one of which is the anisotropy field of stochastic domains, and the other is the magnetoelastic anisotropy field due to residual macrostresses.

Induced Magnetic Anisotropy of Sputter NiFe Thin Films on Thin Tantalum Nitride Underlayer

1995 ◽  
Vol 384 ◽  
Author(s):  
T. Yeh ◽  
L. Berg ◽  
J. Falenschek ◽  
J. Yue
Keyword(s):  
Magnetic Anisotropy ◽  
Anisotropy Field ◽  
Tantalum Nitride ◽  
X Ray Diffraction ◽  
Crystalline Orientation ◽  
X Ray ◽  
Anisotropic Stress ◽  
Magnetoelastic Energy ◽  
Thermal Oxide ◽  
Induced Magnetic Anisotropy

ABSTRACTThe structure and properties of sputter NiFe thin film deposited on both thermal oxide and thin tantalum nitride have been studied. The magnetic anisotropy field HK increases to 8.2 Oe when the NiFe film was deposited on a thin tantalum nitride underlayer. Anisotropic stress was found on the sample film with tantalum nitride underlayer. Results of X-ray diffraction show that a thin tantalum nitride underlayer appears to promote a preferred crystalline orientation formation of the NiFe film. The induced magnetic anisotropy is attributed to the formation of the preferred crystalline orientation and the induced anisotropic magnetoelastic energy which is associated with the anisotropic stress of the sample film.

Microstructure and Physical Properties of Clay-Polymer Composites

2000 ◽  
Vol 628 ◽  
Author(s):  
T.N. Blanton ◽  
D. Majumdar ◽  
S.M. Melpolder
Keyword(s):  
Composite Materials ◽  
Physical Properties ◽  
Polymer Composites ◽  
Basal Plane ◽  
X Ray Diffraction ◽  
X Ray ◽  
Layered Clay

ABSTRACTClay-polymer nanoparticulate composite materials are evaluated by the X-ray diffraction technique. The basal plane spacing provided information about the degree of intercalation and exfoliation of the 2: 1 layered clay structure. Both intercalation and exfoliation are controlled by the identity of the polymer and the clay:polymer ratio.

Annealing effect on the optical and photoelectrochemical properties of lead oxide

2018 ◽  
Vol 84 (3) ◽  
pp. 30301 ◽  
Author(s):  
Wided Zerguine ◽  
Djamila Abdi ◽  
Farid Habelhames ◽  
Meriem Lakhdari ◽  
Hassina Derbal-Habak ◽  
...  
Keyword(s):  
Lead Oxide ◽  
Orthorhombic Phase ◽  
Heat Treatments ◽  
Photoelectrochemical Properties ◽  
X Ray Diffraction ◽  
Vis Spectroscopy ◽  
Size And Morphology ◽  
Two Phases ◽  
P Type ◽  
The Relationship

Effect of the annealing oxidation time of electrodeposited lead (Pb) on the phase formation of lead oxide (PbO) films is reported. The phase structure, optical properties, size and morphology of the films were investigated by scanning electron microscopy, X-ray diffraction and UV-vis spectroscopy. The relationship between structur and photoelectrochemical properties was investigated. Thin films of PbO produced via air annealing of electrodeposited lead consist of a mixture of two phases, orthorhombic (o-PbO) and tetragonal (t-PbO), that determine the material properties and effectiveness as absorber layer in a photoelectrochemical device. The proportion of tetragonal t-PbO increases for longer heat treatments. After 40 h, the sample consists mainly of tetragonal t-PbO. The p-type semiconducting behavior of lead oxide was studied by photocurrent measurements. Different heat treatments yield variations in the ratio of tetragonal to orthorhombic lead oxide that effect on device performances, where devices with a higher content of tetragonal t-PbO show higher photocurrent than with the orthorhombic phase.

scholarly journals Fabrication of Mesostructured Silica and Titania Rods on Substrates by Using Polycarbonate Membranes

2010 ◽  
Vol 2010 ◽  
pp. 1-4 ◽  
Author(s):  
Norihiro Suzuki ◽  
Yusuke Yamauchi
Keyword(s):  
Electron Microscope ◽  
Longitudinal Axis ◽  
Sem Images ◽  
One Pot ◽  
Polycarbonate Membrane ◽  
Entire Area ◽  
Transmission Electron ◽  
Polycarbonate Membranes ◽  
Fibrous Morphology ◽  
Oriented Parallel

By using the polycarbonate membrane a template, mesoporous silica rods are fabricated on a silicon substrate in one pot. From scanning electron microscope (SEM) images, the creation of fibrous morphology is confirmed over the entire area. The diameter of the obtained rods is consistent with that of the template. Transmission electron microscope (TEM) images revealed that the tubular mesochannels are uniaxially oriented parallel to the longitudinal axis of the silica rods. The mesoporous titania rods with anatase crystalline frameworks are also fabricated.

Magnetic Anisotropy in Electrodeposited CO Films and spin-valves on Gaas Substrates

1999 ◽  
Vol 562 ◽  
Author(s):  
K. Attenborough ◽  
M. Cerisier ◽  
H. Boeve ◽  
J. De Boeck ◽  
G. Borghs ◽  
...  
Keyword(s):  
Magnetic Anisotropy ◽  
Buffer Layer ◽  
Structural Properties ◽  
Easy Axis ◽  
Spin Valve ◽  
X Ray Diffraction ◽  
X Ray ◽  
Cu Films ◽  
Gaas Substrates ◽  
Unique Spin

ABSTRACTWe have studied the magnetic and structural properties of thin electrodeposited Co and Cu layers grown directly onto (100) n-GaAs and have investigated the influence of a buffer layer. A dominant fourfold anisotropy with a uniaxial contribution is observed in 10 nm Co electrodeposited films on GaAs. An easy axis is observed in the [001] GaAs direction with two hard axes of differing coercivities parallel to the [011] and [011] directions. For thicker films the easy axes in the [001] direction becomes less pronounced and the fourfold anisotropy becomes less dominant. Co films of similar thicknesses deposited onto an electrodeposited Cu buffer layer were nearly isotropic. From X-ray diffraction 21 nm Co layers on GaAs were found to be hcp with the c-axis tending to be in the plane of the film. The anisotropy is ascribed to the Co/GaAs interface and is held responsible for the unique spin-valve properties seen recently in electrodeposited Co/Cu films.

Effect of Thickness on Mechanically Tunable Magnetic Anisotropy of FeGa Thin Films Deposited on Flexible Substrates

2015 ◽  
Vol 815 ◽  
pp. 227-232 ◽  
Author(s):  
Ying Yu ◽  
Shu Hong Xie ◽  
Qing Feng Zhan
Keyword(s):  
Thin Films ◽  
Magnetic Properties ◽  
Magnetic Anisotropy ◽  
Effective Strain ◽  
Anisotropy Field ◽  
Saturation Field ◽  
Effective Anisotropy ◽  
Magnetostriction Constant ◽  
The Difference ◽  
Different Strains

A practical way to manipulate the magnetic anisotropy of magnetostrictive FeGa thin films grown on flexible polyethylene terephthalate (PET) substrates is introduced in this study. The effect of film thickness on magnetic properties and magnetostriction constant of polycrystalline FeGa thin films was investigated. The anisotropy field Hk of flexible FeGa films, i.e., the saturation field determined by fitting the hysteresis curves measured along the hard axis, was enhanced with increasing the tensile strain applied along the easy axis of the thin films, but this enhancement via strain became unconspicuous with increasing the thickness of FeGa films. In order to study the magnetic sensitivity of thin films responding to the external stress, we applied different strains on these films and measure the corresponding anisotropy field. Moreover, the effective magnetostriction constant of FeGa films was calculated from the changes of both anisotropy field and external strain based on the Villari effect. A Neel’s phenomenological model was developed to illustrate that the effective anisotropy field of FeGa thin films was contributed from both the constant volume term and the inverse thickness dependent surface term. Therefore, the magnetic properties for the volume and surface of FeGa thin films were different, which has been verified in this work by using vibrating sample magnetometer (VSM) and magneto-optic Kerr effect (MOKE) system. The anisotropy field contributed by the surface of FeGa film and obtained by MOKE is smaller than that contributed by the film volume and measured by VSM. We ascribed the difference in Hk to the relaxation of the effective strain applied on the films with increasing the thickness of films.

The Effect of Ti Addition on the Microstructure and Fracture Toughness of Bn-Al Composite Materials Synthesized by Vacuum Infiltration

2013 ◽  
Vol 58 (2) ◽  
pp. 509-512 ◽  
Author(s):  
W. Chao ◽  
X. Xiangxin ◽  
C. Xiaozhou ◽  
Y. He ◽  
Ch. Gongjin
Keyword(s):  
Fracture Toughness ◽  
Composite Materials ◽  
Vacuum Infiltration ◽  
X Ray Diffraction ◽  
Al Composite ◽  
Vacuum Atmosphere ◽  
Diffraction Peaks ◽  
Xrd Patterns ◽  
Ti Content ◽  
Ti Addition

In this paper, we studied the effect of Ti addition on the microstructure and fracture toughness of Boron nitride- Aluminum (BN-Al) composite materials that were synthesized by vacuum infiltration. The BN-Al composite materials were fabricated by preheating the [Ti+BN] preforms at 1700º for 1 hour before Al alloys were infiltrated into the preforms in a vacuum atmosphere at 1100º for 2 hours. X-ray diffraction (XRD) patterns showed that the diffraction peaks of titanium diboride (TiB2) appeared when the [Ti+BN] preforms were preheated. It is thought that metal Al protected are visible and this could be achieved by the generation of TiB2 when Al infiltrated into the preform from fractography. The matching fracture toughness of the [Ti+BN] preforms gradually improve when Ti content was increased.

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