AC Magnetic Measurements on Superconductors

2011 ◽  
Vol 1 (3) ◽  
pp. 53-66
Author(s):  
Philippe Laurent ◽  
Jean-François Fagnard ◽  
Philippe Vanderbemden
Keyword(s):  
Magnetic Properties ◽  
Temperature Distribution ◽  
Magnetic Measurements ◽  
Sampling Rate ◽  
Data Acquisition System ◽  
Magnetic Data ◽  
Magnetic Characterization ◽  
Set Up ◽  
Cryogenic Conditions

This work describes the design and realisation of an apparatus to measure simultaneously the AC magnetic properties and the temperature distribution on the top surface of bulk superconducting samples (up to 32 mm in diameter) in cryogenic conditions (temperature range 78-120 K). First the authors describe the experimental set-up used for simultaneous thermal and magnetic characterization of the sample. Next, the authors describe the practical considerations required for generating the large AC magnetic fields, possibly in the presence of DC fields. Then the authors present the data acquisition system allowing both temperature and magnetic data to be recorded at high a sampling rate." The performances and limitations of the system are discussed.

AC Magnetic Measurements on Superconductors

2013 ◽  
pp. 208-222
Author(s):  
Philippe Laurent ◽  
Jean-François Fagnard ◽  
Philippe Vanderbemden
Keyword(s):  
Magnetic Properties ◽  
Temperature Distribution ◽  
Magnetic Measurements ◽  
Sampling Rate ◽  
Data Acquisition System ◽  
Magnetic Data ◽  
Magnetic Characterization ◽  
Set Up ◽  
Cryogenic Conditions

This work describes the design and realisation of an apparatus to measure simultaneously the AC magnetic properties and the temperature distribution on the top surface of bulk superconducting samples (up to 32 mm in diameter) in cryogenic conditions (temperature range 78-120 K). First the authors describe the experimental set-up used for simultaneous thermal and magnetic characterization of the sample. Next, the authors describe the practical considerations required for generating the large AC magnetic fields, possibly in the presence of DC fields. Then the authors present the data acquisition system allowing both temperature and magnetic data to be recorded at high a sampling rate.” The performances and limitations of the system are discussed.

DC and AC Measurements of Magnetite Nanoparticulates and Implications for Nonlinear Response

2008 ◽  
Vol 1138 ◽  
Author(s):  
Silvia Liong ◽  
Ricky Lamar Moore
Keyword(s):  
Particle Size ◽  
Magnetic Properties ◽  
Polymer Composites ◽  
Magnetic Measurements ◽  
Bulk Material ◽  
Low Frequency ◽  
Anisotropy Field ◽  
Coaxial Line ◽  
Magnetic Data ◽  
Order Of Magnitude

AbstractThis paper discusses preparation, characterization and measurement of linear DC and AC magnetic properties of magnetite (Fe3O4) nanoparticles (size ranges of 7-50 nm and 5 microns) and polymer composites of those particulates. Selected data and analysis are taken from the PhD thesis of Liong [1]. The goal of this research is to obtain magnetic data, specifically magnetization, anisotropy and coercivity as functions of particle size. These will be used as inputs to non linear magnetic simulations and in planning for future nonlinear magnetic measurements. Magnetite nanoparticles were synthesized by chemical coprecipitation, a method that allowed for the production of samples in gram quantities. Vibrating sample magnetometry was used to measure the room-temperature DC magnetization and coercivity of the particulates. Coaxial line impedance measurements were used to measure low frequency and dispersive AC permeability of Fe3O4–polymer composites from 1 Megahertz to 10 Gigahertz. AC data are applied to infer particulate magnetic susceptibility and anisotropy field change with particle size. Particle size was calculated from XTD data and supported by TEM images.Measured DC saturation magnetization and coercivity decreased with particle dimension while anisotropy was calculated to increase. Magnetization data are consistent with models that calculate nanoparticle magnetization as a volumetric average of a spherical bulk material core and a passive outer shell. The shell thickness was calculated at 0.84 nm, very near one lattice constant of bulk Fe3O4, 0.8394 nm. Composites containing particulate volume fractions less than 20% were fabricated. Effective media theory was applied to measured AC composite permeability to extract particle magnetic properties and thereby anisotropy field, which increased by an order of magnitude from the bulk. Permeability decreased with particulate size.

scholarly journals Magnetic properties of synthetic fluorophlogopite mica crystals

2020 ◽  
Vol 1 (5) ◽  
pp. 1464-1471
Author(s):  
Zheng Ma ◽  
Vassil Skumryev ◽  
Martí Gich
Keyword(s):  
Magnetic Properties ◽  
Flexible Substrate ◽  
Magnetic Characterization ◽  
Characterization Of Materials

The contribution of synthetic fluorophlogopite mica needs to be considered in the magnetic characterization of materials grown on this flexible substrate.

Design, synthesis and isolation of a new 1,2,5-selenadiazolidyl and structural and magnetic characterization of its alkali-metal salts

2019 ◽  
Vol 43 (41) ◽  
pp. 16331-16337
Author(s):  
Nikolay A. Semenov ◽  
Ekaterina A. Radiush ◽  
Elena A. Chulanova ◽  
Alexandra M. Z. Slawin ◽  
J. Derek Woollins ◽  
...  
Keyword(s):  
Magnetic Properties ◽  
Alkali Metal ◽  
Electron Acceptor ◽  
Radical Anion ◽  
Metal Salts ◽  
Alkali Metal Salts ◽  
Magnetic Characterization ◽  
Design Synthesis

A new electron acceptor is synthesized and reduced into its radical-anion isolated in the form of two salts with different structures and magnetic properties.

Magnetic Properties and Scaling Behavior in Perovskite–like La0.7(Ba1−xPbx)0.3CoO3 System

2001 ◽  
Vol 674 ◽  
Author(s):  
Chiung-Hsiung Chen ◽  
Ting-Sheng Huang ◽  
Ming-Fong Tai
Keyword(s):  
Magnetic Properties ◽  
Magnetic Measurements ◽  
Mean Field Theory ◽  
Mean Field ◽  
Three Dimensional ◽  
Scaling Behavior ◽  
Magnetic Data ◽  
Crystallographic Structure ◽  
Ferromagnetic Transition ◽  
Diffraction Patterns

ABSTRACTIn this study, we used x-ray diffraction patterns and dc magnetic measurements to investigate the crystallographic structure, magnetic properties and scaling behavior of the distorted perovskite La0.7(Ba1−xPbx)0.3CoO3 (0 ≤ x ≤ 0.5) system with a constant ratio of Co4+/Co3+. Samples with x = 0.0 and 0.1 were crystallized in the cubic structure with a ∼ 7.76 Å whereas samples with x ≥ 0.2 were crystallized in an orthorhombic Pbnm space group with a ∼ b ∼ 5.50 Å and c ∼ 7.85 Å. For all our samples the spin-glass-like behavior were observed in low temperature and low field ranges. The Pb2+ substitution on Ba2+ site does not significantly affect the ferromagnetic transition temperature TC, but does introduce large variation in the magnetic strength. In both the ferromagnetic and paramagnetic states the minimum values of the average effective moments provided by every Co ion occur at x = 0.3. We also observed the scaling behaviors of magnetic data in all samples. The derived values of the critical exponents (β, γ, δ) were consistent with those predicted by mean field theory and a three-dimensional Heisenberg model.

Microstructural Magnetic Characterization of Annealed Non-Oriented Electrical Steel

2018 ◽  
Vol 915 ◽  
pp. 190-195
Author(s):  
Evangelos Hristoforou ◽  
Athanasios G. Mamalis
Keyword(s):  
Magnetic Properties ◽  
Magnetic Permeability ◽  
Electrical Steel ◽  
Barkhausen Noise ◽  
Magnetic Barkhausen Noise ◽  
Magnetic Characterization ◽  
Microstructural Changes ◽  
Wide Range ◽  
Nondestructive Characterization

The present paper investigates the utilization of the magnetic Barkhausen noise and magnetic permeability methods for the nondestructive characterization of annealed non-oriented electrical steel samples which were isothermally annealed in a wide range of temperatures (400°C – 950°C) and subsequently cooled in air. The resulting magnetic properties were compared with the microstructural changes occurring during annealing.

Initial Study of Magnetic Characterization of Barium Hexaferrite with the Addition of Cobalt Oxide Prepared by Powder Metallurgy Process

2021 ◽  
Vol 1028 ◽  
pp. 38-43
Author(s):  
Trie J.S. Wibowo ◽  
Supono A. Dwiwanto ◽  
Tony Kristiantoro ◽  
Togar Saragi ◽  
Risdiana
Keyword(s):  
Magnetic Properties ◽  
Powder Metallurgy ◽  
Cobalt Oxide ◽  
Barium Hexaferrite ◽  
Xrd Analysis ◽  
Initial Study ◽  
Magnetic Characterization ◽  
Powder Metallurgy Process ◽  
Metallurgy Process

Co3O4 powder was added to barium hexaferrite by powder metallurgy process to determine its effect on the magnetic properties. The variation of the addition of Co3O4 are 0.0, 0.5, 1.0, 2.0, 3.0, and 5.0 wt%. Characterization and magnetic testing included density calculation, Permagraph test, and XRD were performed in order to elucidate the effect of Co3O4 addition to its structure and magnetic properties of barium hexaferrite. The magnetic density obtained was in the ranges of 3.2 - 4.35 g/cm3. From the permagraph test, it is found that the value of remanence (Br) was in between 1.18 and 1.5 kG. The value of coercivity (Hc) was in the range of 0.594 - 3.366 kOe, and the maximum product energy (BHmax) was found to be in between 0.07 and 0.48 MGOe. From the XRD analysis, it was found that two types of barium hexaferrite were formed, namely barium hexaferrite type M(BaFe12O19) and X(Ba2Fe30O46). It is concluded that the addition of the Co3O4 compound increased the value of magnetic density and decreased magnetic properties.

Synthesis and Characterization of New Composite Oxides Related to the 2H-Perovskite Structure Type

1998 ◽  
Vol 547 ◽  
Author(s):  
J. B. Claridge ◽  
H.-C. zur Loye
Keyword(s):  
Magnetic Properties ◽  
Low Temperature ◽  
Structure Type ◽  
Magnetic Data ◽  
Antiferromagnetic Coupling ◽  
Synthesis And Characterization ◽  
Composite Oxides ◽  
Rhodium Oxides ◽  
Ordered State

AbstractThe synthesis, structural characterization, and magnetic properties of three strontium rhodium oxides Sr6Rh5O15, Sr4Rh3O9+δ, and Sr9Rh7O21+δ, is presented. While Sr6Rh5O15 is an example of a commensurate n = 1 member of the A3n+3A'nBn+3O6n+9 family of oxides, Sr4Rh3O9+δ, and Sr9Rh7O21+°, are examples of incommensurate n =2 and n = 3 members. Sr6Rh5O15 crystallizes in space group R32, a = 19.3197(2) Å, c = 13.0418(1) Å. The Sr6Rh5O15 structure is a superstructure of the Ba6Ni5O15 structure type. Sr4Rh3O9+δ, and Sr9Rh7P21+δ crystallize in the superspace group with lattice parameters of a = 9.6007(6), c1 = 2.6881(2), c2 = 4.2373(3), and a = 9.6127(6), c1 = 2.6769(2), c2 = 4.252(1), respectively. Their magnetic data are consistent with antiferromagnetic coupling between the chains leading to an ordered state at low temperature.

Characterization of Electron Beam Welded Non-Oriented Electrical Steel with Magnetic Barkhausen Noise

2014 ◽  
Vol 605 ◽  
pp. 39-42 ◽  
Author(s):  
Polykseni Vourna
Keyword(s):  
Mechanical Properties ◽  
Magnetic Properties ◽  
Electron Beam ◽  
Electrical Steel ◽  
Electron Beam Welding ◽  
Magnetic Measurements ◽  
Barkhausen Noise ◽  
Magnetic Barkhausen Noise ◽  
Electrical Steels

In this paper the influence of Electron Beam Welding (EBW) on the microstructure, mechanical and magnetic properties of Non-Oriented Electrical steels was presented and evaluated. Single pass welds free of defects were produced at welding speeds and pulsed currents following a predesigned protocol. The samples microstructure and the macrohardness tests were concluded with the magnetic measurements (Barkhausen Noise) in order to correlate the structural and mechanical properties with the magnetizing behavior of Non-Oriented Electrical Steel.

Synthesis and Characterization of PEG-Modified ZnGd0.1Fe1.9O4 Ferrite Nanoparticles for Interstitial Hyperthermia to Tumor

2007 ◽  
Vol 334-335 ◽  
pp. 1209-1212
Author(s):  
Ai Hua Yao ◽  
De Ping Wang ◽  
Wen Hai Huang
Keyword(s):  
Magnetic Properties ◽  
Remanent Magnetization ◽  
Magnetic Measurements ◽  
Magnetic Behavior ◽  
Ferrite Nanoparticles ◽  
Slight Reduction ◽  
Interstitial Hyperthermia ◽  
Coprecipitation Process ◽  
Good Biocompatibility

PEG-modified ZnGd0.1Fe1.9O4 ferrite nanoparticles were synthesized by a coprecipitation process combined with a microemulsion technique. The effect of modification on the structure, magnetic properties of ZnGd0.1Fe1.9O4 nanoparticles was also investigated by XRD, FTIR, TEM and VSM. The results showed immobilizing PEG on the surfaces of magnetic nanoparticles effectively improved their dispersibility. Magnetic measurements indicated that the as-prepared PEG-modified nanoparticles exhibited relatively high magnetic properties, although a slight reduction in saturation and remanent magnetization were observed compared with unmodified samples. Therefore, with promising high magnetic behavior and potentially good biocompatibility, PEG-modified ZnGd0.1Fe1.9O4 ferrite nanoparticles would be feasible as thermoseeds for interstitial hyperthermia to tumor.

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