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Search Results: 1 - 10 of 16137 matches for " Terfenol-D "
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First Evidence of Surface SH-Wave Propagation in Cubic Piezomagnetics  [PDF]
Aleksey Zakharenko
Journal of Electromagnetic Analysis and Applications (JEMAA) , 2010, DOI: 10.4236/jemaa.2010.25037
Abstract: This theoretical work provides with results of characteristics calculation of the ultrasonic surface Zakharenko waves (USZWs) existing in piezomagnetic cubic monocrystals of class m3m that can be readily used for non-destructive testing. The piezomagnetic waves propagate in direction [101] corresponding to relatively easy magnetization for the following piezomagnetics: Galfenol, Terfenol-D, and CoFe2O4 with cubic structures. The phase velocities of the USZW-waves and the coefficient of magnetomechanical coupling (CMMC) K2 were calculated for the crystals. It was found that the coefficient K2 for piezomagnetics with Km2 > 1/3 and Km2 >> 1/3 is about 8% to 9%, where K2 = 2 (VUSZW,o – VUSZW,c)/VUSZW,o and Km2 = h2/(Cμ). Knowledge of piezomagnetic properties of cubic crystals makes possible the use of them in new products utilizing the phenomenon called the magnetoelectric effect. Also, this study is useful for possible application of cubic piezomagnetics in composite structures consisting of piezoelectric and (or) piezomagnetic materials and in the microwave technology. This broadens choice of possible piezomagnetic materials for utilization in various technical devices.
THE EFFECT STRESS ON THE MAGNETOSTRICTION IN TWIN FREE SINGLE CRYSTALS Tb y Dy 1-y (Fe 1-x T x) 2 (T=Al,Mn)
THE EFFECT STRESS ON THE MAGNETOSTRICTION IN TWIN- FREE SINGLE CRYSTALS Tb_y Dy_(1-y) (Fe_(1-x) T_x)_2 (T=Al,Mn)

YXLi,GZXu,JPQu,FGLiu,BW Wang Hebei University of Technology,Tianjin,China C Zhao Tianjin University,Tianjin,China SX Gao Hebei Normal University,Shijiazhuang,China CC Tang,GHWu,JHWang,JDu,WSZhan State Key Laboratory for Magnetism,
Y.X.Li
,G.Z.Xu,J.P.Qu,F.G.Liu and B.W. Wang Hebei University of Technology,Tianjin,China C. Zhao Tianjin University,Tianjin,China S.X. Gao Hebei Normal University,Shijiazhuang,China C.C. Tang,G.H.Wu,J.H.Wang,J.Du and W

金属学报(英文版) , 1999,
Abstract: Magnetostriction at room temperature under various conditions of compressive prestress and applied fields in Tb yDy 1-y (Fe 1-x T x) 2 (T=Al,Mn) twin-free single crystals were investigated. The substitution of Al or Mn for Fe lowers the magnetostriction un-der ordinary temperature and pressure, but it also decreases the saturation field, which enables these materials with potential benefits for applications.
Magnetic properties of composites of Tb0.28Dy0.72Fe2 and polyvinylidene fluoride

Cai Ning,Zhai Jun-Yi,Shi Zhan,Lin Yuan-Hua,Nan Ce-Wen,

中国物理 B , 2004,
Abstract: Bi-ferroic particulate composites with Tb_{0.28}Dy_{0.72}Fe_2 (Terfenol-D) particles randomly dispersed in ferroelectric polyvinylidene fluoride matrix prepared by a simple hot-pressing procedure were investigated. With increasing concentration of Terfenol-D, the magnetic susceptibility, saturation magnetization and initial permeability of the composites increases. The dependence of the effective magnetostriction on applied bias for the composites is similar to that for bulk Terfenol-D, but the effective magnetostriction strongly depends on the volume fraction of Terfenol-D. The observed behaviour of the composite is reasonably described by using effective medium theories.
Properties of the magnetostrictive composite materials with the polyurethane matrix reinforced with Terfenol-D particles
L.A. Dobrzański,A.E. Tomiczek,A.W. Pacyna
Journal of Achievements in Materials and Manufacturing Engineering , 2012,
Abstract: Purpose: The aim of this work is to obtain functional composite materials and to observe changes of magnetic properties of samples with different particle size distributions of magnetostrictive Terfenol-D (Tb0.3Dy0.7Fe1.9) powder. The influence of the concentration and particles size of the Tb0.3Dy0.7Fe1.9 on magnetic properties were investigated as function of applied magnetic field intensity, temperature and frequency.Design/methodology/approach: The investigated samples were obtained by casting of the composite materials with the polyurethane matrix reinforced with Tb0.3Dy0.7Fe1.9 particles. Magnetizations versus applied field curves were registered using the Oxford Instruments Ltd. vibrating sample magnetometer (VSM). Volume magnetic susceptibility was determined as temperature function on the Cahn RG automatic electrobalance (Ventron Instrumens, USA). Testing of the magnetic permeability in function of frequency was made using the Maxwell-Wien bridge system and the electrical properties were made by the resistivity measurements.Findings: Analysis establishes a direct connection between physical properties and structural characteristics of the Tb0.3Dy0.7Fe1.9 powder size: the increases of particle size distribution of Tb0.3Dy0.7Fe1.9 powder in composite materials amplify the magnetic responses and - at the same time - causing growth of resistivity values also. Moreover, in the investigated frequency range, no effect was observed of frequency on the susceptibility value for the particular material, which suggests possibility of using these materials in the high-frequency magnetic fields.Practical implications: The polyurethane matrix in investigated composite materials causes growth of resistivity, limiting these way losses for eddy currents at the high operating frequency of the transducers.Originality/value: The obtained results show the possibility of manufacturing the magnetostrictive composite materials based on the Tb0.3Dy0.7Fe1.9 particles, with desired physical properties (including electrical one) in cost effective way in comparison to conventional giant magnetostrictive materials (GMM).
The inverse magnetostrictive effect in Tb0.3Dy0.7Fe2
Tb0.3Dy0.7Fe2单晶中巨磁致伸缩的逆效应

Zhang Hui,Zeng De-Chang,
张辉
,曾德长

中国物理 B , 2010,
Abstract: The inverse magnetostrictive effect, also called magnetomechanical effect, in Terfenol-D material, has been investigated in this paper. Based on Stoner-Wohlfarth (SW) model, taking into account magnetocrystalline and stress-induced anisotropy energy, and following the free energy minimization procedure, direction cosines of magnetization in Terfenol-D single crystal in demagnetized state have been obtained as a function of the compressive stress. The nonlinear equations for equilibrium have been solved numerically. The results indicated that under compressive stress, magnetic anisotropy in Terfenol-D is determined by a competition between magnetocrystalline and stress-induced anisotropy energy, and changes from cubic symmetry to uniaxial. A comparison between experimental and numerical results showed that there is a maximum magnetostriction in Terfenol-D at a certain stress. According to our numerical results, experimental observations that compressive stress makes Terfenol-D hard to be magnetized and leads to the maximum magnetostriction can be explained. The computation in this paper presents a more accurate approach to similar investigations, and its numerical results would be helpful for a better understanding of magnetization process of similar materials.
Structure, magnetic properties and giant magnetostriction studies in [Tb/Fe/Dy] n nano-multilayer film
XiaoDong Li,ZhenJie Zhao,SuMei Huang,LiKun Pan,YiWei Chen,XieLong Yang,Zhuo Sun
Chinese Science Bulletin , 2009, DOI: 10.1007/s11434-009-0040-7
Abstract: [Tb/Fe/Dy] n nano-multilayer films, with precise composition of Tb0.27Dy0.73Fe2, were prepared by the multi-targets magnetron sputtering technique at room temperature (sample A) and 300°C substrate temperature (sample B). Both of the nano-multilayer films show columnar structures perpendicular to the film plane according to the scanning electron microscopy results. The magnetic hysteresis loops and the giant magnetostriction (GMS) property of the two samples indicate the perpendicular anisotropy in them. In spite of the perpendicular anisotropy, both of the samples present GMS effect. In a very low applied field of 0.18 T, the GMS value in sample B is 89.3 ppm, which is about four times of that in sample A, 23.5 ppm. The good low-field GMS effect in sample B might attribute to the Laves phase of R-Fe2 segregated from the amorphous matrix under the thermal annealing of the substrate. The relation between the magnetization process and GMS property of the perpendicular anisotropy nano-multilayer films is further investigated.
Simulation on Domain Rotation Path and Magnetostriction of Terfenol-D Alloy
Jiuchun YAN,Wenbo HAN,Xiaoqiu XIE,Shiqin YANG,

材料科学技术学报 , 2001,
Abstract: Based on a simplified domain rotation model, the rotation path of internal domains and corresponding magnetostriction of 112], 111] oriented single Terfenol-D crystals under compressive prestresses have been simulated. Comparisons with results of experiment and other calculation have been made. Results of simulation showed that the 111] oriented single crystal has better low-field magnetostriction properties than the 112] oriented one. Under a compressive prestress of 10 MPa, up to 2300x10(-6) saturation magnetostriction of 111] oriented crystal has been obtained at 800 Oe, while for 112] oriented, 1600x10(-6) maximum magnetostriction has been reached at 1000 Oe.
Structure, magnetic properties and giant magnetostriction studies in [Tb/Fe/Dy] n nano-multilayer film

XiaoDong Li,ZhenJie Zhao,SuMei Huang,LiKun Pan,YiWei Chen,XieLong Yang,Zhuo Sun,

科学通报(英文版) , 2009,
Abstract: Tb/Fe/Dy] n nano-multilayer films, with precise composition of Tb0.27Dy0.73Fe2, were prepared by the multi-targets magnetron sputtering technique at room temperature (sample A) and 300°C substrate temperature (sample B). Both of the nano-multilayer films show columnar structures perpendicular to the film plane according to the scanning electron microscopy results. The magnetic hysteresis loops and the giant magnetostriction (GMS) property of the two samples indicate the perpendicular anisotropy in them. In spite of the perpendicular anisotropy, both of the samples present GMS effect. In a very low applied field of 0.18 T, the GMS value in sample B is 89.3 ppm, which is about four times of that in sample A, 23.5 ppm. The good low-field GMS effect in sample B might attribute to the Laves phase of R-Fe2 segregated from the amorphous matrix under the thermal annealing of the substrate. The relation between the magnetization process and GMS property of the perpendicular anisotropy nano-multilayer films is further investigated. Supported by the National Natural Science Foundation of China (Grant Nos. 60477003, 10774046)
FEM modelling of magnetostrictive composite materials
L.A. Dobrzański,A. Tomiczek,G. Dziatkiewicz
Archives of Materials Science and Engineering , 2012,
Abstract: Purpose: The paper presents a numerical model for the analysis of magnetostriction in composite materials in polymer matrix reinforced by Tb0.3Dy0.7Fe1.9 particles. The properties were determined by taking into account the applied stresses and magnetic field intensity.Design/methodology/approach: The finite element method for simulation the magnetostriction phenomenon was established by theoretical analysis based on experimental results.Findings: Thanks to the finite element method the numerical model has been formulated, enabling to simulate behavior of dynamically exciting rod with the nonlinear constituted model of magnetostrictive effect. The results received from experiments and simulations confirmed accuracy of this model for operating conditions, enabling a selection of magnetostrictive composite material with polymer matrix reinforced with Tb0.3Dy0.7Fe1.9 particles for specific application.Research limitations/implications: It was confirmed that using the finite element method can be a way for reducing the investigation cost. This paper proposes analysis which is efficient with respect to the number of simplifications in numerical model and accuracy of results.Practical implications: The proposed method could be helpful in the design process of magnetostrictive composite materials.Originality/value: Modelling based on the finite element method allows to simulating behavior of dynamically exciting rod with the nonlinear constituted model of magnetostriction phenomenon.
Physical properties of magnetostrictive composite materials with the polyurethane matrix
L.A. Dobrzański,A.E. Tomiczek,A. Szewczyk,K. Piotrowski
Archives of Materials Science and Engineering , 2012,
Abstract: Purpose: The purpose of this study was to determine the thermal and electrical conductivity of composite materials with the polyurethane matrix reinforced with Tb0.3Dy0.7Fe1.9 particles with different particle size distributions and varying volume concentration.Design/methodology/approach: The investigated samples were obtained by casting of the composite materials with the polyurethane matrix reinforced with Tb0.3Dy0.7Fe1.9 particles. There were determined the samples density, electrical properties (by a resistivity measurements), thermal conductivity (by Physical Property Measurement System with thermal transport option), as well as the metallographic investigations (by stereo microscope).Findings: It was found from obtained results that the resistivity value for composite materials filled with larger particle size Tb0.3Dy0.7Fe1.9 was lower than the smaller particles size filled composites. Moreover, it may be noticed that thermal conductivity has an approximate value for different Tb0.3Dy0.7Fe1.9 particle size and the same its volume fraction in matrix. Simultaneously it was also observed that the thermal conductivity of the composite materials did not depend on the temperature within the tested range from 293 to 333 K.Research limitations/implications: Contributes to research on structure and physical properties of magnetostrictive composite materials with the polyurethane matrix reinforced with Tb0.3Dy0.7Fe1.9 particles.Practical implications: The polyurethane matrix in investigated composite materials causes growth of resistivity, limiting this way losses for eddy currents at the high operating frequency of the transducers.Originality/value: The obtained results show the possibility of manufacturing the magnetostrictive composite materials based on the Tb0.3Dy0.7Fe1.9 particles, with desired physical properties (including thermal and electrical one) in cost effective way in comparison to conventional giant magnetostrictive materials (GMM).
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