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X X Zhang - One of the best experts on this subject based on the ideXlab platform.
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realization of magnetic field induced reversible Martensitic Transformation in nicomnga alloys
Applied Physics Letters, 2007Co-Authors: S Y Yu, G H Wu, J Chen, Baowen Zhang, X X ZhangAbstract:Effect of a magnetic field on Martensitic Transformation in the NiCoMnGa alloys was investigated. A field-induced reversible Martensitic Transformation from the Martensitic phase of low magnetization to the parent phase of high magnetization has been realized. The substitution of Co for Ni atoms has turned the magnetic ordering of the parent phase from partially antiferromagnetic to ferromagnetic, resulting in a large magnetization change across the Transformation, which dramatically enhances the magnetic field driving force. The Transformation temperature can be downshifted by magnetic field at a rate up to 14K∕T in Ni37Co13Mn32Ga18. Other mechanism details were also discussed.
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magnetic field induced Martensitic Transformation and large magnetoresistance in nicomnsb alloys
Applied Physics Letters, 2007Co-Authors: S Y Yu, G H Wu, J Chen, Baowen Zhang, X X ZhangAbstract:Magnetic field-induced Martensitic Transformation was realized in Ni50−xCoxMn39Sb11 alloys. The partial substitution of Co for Ni has turned the antiferromagnetically aligned Mn moments in the starting material Ni50Mn39Sb11 into a ferromagnetic ordering, raising the magnetization at room temperature from 8emu∕g for NiMnSb to ∼110emu∕g for Ni41Co9Mn39Sb11. In the same quaternary sample, a magnetization difference up to 80emu∕g was measured across the Martensitic Transformation, and the Transformation temperature (T0=259K) could be lowered by 35K under a field of 10T. Also a magnetoresistance over 70% was observed through this field-induced Transformation.
G H Wu - One of the best experts on this subject based on the ideXlab platform.
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realization of magnetic field induced reversible Martensitic Transformation in nicomnga alloys
Applied Physics Letters, 2007Co-Authors: S Y Yu, G H Wu, J Chen, Baowen Zhang, X X ZhangAbstract:Effect of a magnetic field on Martensitic Transformation in the NiCoMnGa alloys was investigated. A field-induced reversible Martensitic Transformation from the Martensitic phase of low magnetization to the parent phase of high magnetization has been realized. The substitution of Co for Ni atoms has turned the magnetic ordering of the parent phase from partially antiferromagnetic to ferromagnetic, resulting in a large magnetization change across the Transformation, which dramatically enhances the magnetic field driving force. The Transformation temperature can be downshifted by magnetic field at a rate up to 14K∕T in Ni37Co13Mn32Ga18. Other mechanism details were also discussed.
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magnetic field induced Martensitic Transformation and large magnetoresistance in nicomnsb alloys
Applied Physics Letters, 2007Co-Authors: S Y Yu, G H Wu, J Chen, Baowen Zhang, X X ZhangAbstract:Magnetic field-induced Martensitic Transformation was realized in Ni50−xCoxMn39Sb11 alloys. The partial substitution of Co for Ni has turned the antiferromagnetically aligned Mn moments in the starting material Ni50Mn39Sb11 into a ferromagnetic ordering, raising the magnetization at room temperature from 8emu∕g for NiMnSb to ∼110emu∕g for Ni41Co9Mn39Sb11. In the same quaternary sample, a magnetization difference up to 80emu∕g was measured across the Martensitic Transformation, and the Transformation temperature (T0=259K) could be lowered by 35K under a field of 10T. Also a magnetoresistance over 70% was observed through this field-induced Transformation.
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Martensitic Transformation and shape memory effect in ferromagnetic heusler alloy ni2fega
Applied Physics Letters, 2003Co-Authors: Zhuhong Liu, Yanxiang Cui, Wanyan Wang, G H Wu, M.-h. Zhang, Xixiang Zhang, Yongli Zhou, Gang XiaoAbstract:We have synthesized ferromagnetic Heusler alloy Ni2FeGa using the melt-spinning technique. The Ni2FeGa ribbon, having a high chemical ordering L21 structure, exhibits a thermoelastic Martensitic Transformation from cubic to orthorhombic structure at 142 K and a preMartensitic Transformation. The alloy has a relatively high Curie temperature of 430 K, a magnetization of 73 Am2/kg, and a low saturated field of 0.6 T. The textured samples with preferentially oriented grains show a completely recoverable two-way shape memory effect with a strain of 0.3% upon the thermoelastic Martensitic Transformation.
R Kainuma - One of the best experts on this subject based on the ideXlab platform.
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microstructure and Martensitic Transformation in the fe mn al ni shape memory alloy with b2 type coherent fine particles
Applied Physics Letters, 2012Co-Authors: Toshihiro Omori, M Nagasako, M Okano, K Endo, R KainumaAbstract:Microstructure and Martensitic Transformation yielding a magnetic change were investigated for Fe43.5Mn34Al15Ni7.5 alloy with B2-type fine precipitates. Thermoelastic Martensitic Transformation from the ferromagnetic parent phase to the weak magnetic martensite with a nano-twinned fcc structure was confirmed. High-angle annular dark-field scanning transmission electron microscopic observation revealed that a β particle of about 10 nm maintains coherency with the matrix martensite phase, even though distorted due to the Martensitic Transformation. The Martensitic Transformation temperatures decreased about 75 K by application of a magnetic field of 70 kOe and magnetic field-induced reverse Martensitic Transformation was confirmed.
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kinetic arrest behavior in Martensitic Transformation of nicomnsn metamagnetic shape memory alloy
Journal of Alloys and Compounds, 2011Co-Authors: R Y Umetsu, Kouhei Ito, W Ito, Keiichi Koyama, T Kanomata, K Ishida, R KainumaAbstract:Abstract High-field magnetic measurements were carried out in order to investigate behaviors of field-induced reverse Martensitic Transformation and kinetic arrest of NiCoMnSn metamagnetic shape memory alloy. In the thermomagnetization curves, it was confirmed that the reverse Martensitic Transformation temperature decreases 67 K by applying magnetic field of 5 T, while in the magnetic field cooling process under 5 T, Martensitic Transformation does not occur down to low temperatures. Equilibrium magnetic field, defined from the critical magnetic fields of the metamagnetic evidence in the magnetization curves, exhibits almost constant below about 100 K, suggesting that the entropy change becomes zero, which is considered to cause kinetic arrest behavior.
Christopher A Schuh - One of the best experts on this subject based on the ideXlab platform.
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crystal orientation dependence of the stress induced Martensitic Transformation in zirconia based shape memory ceramics
Acta Materialia, 2016Co-Authors: Xiao Mei Zeng, Alan Lai, Chee Lip Gan, Christopher A SchuhAbstract:Abstract Small volume samples of zirconia can survive stress-induced Martensitic Transformation without cracking, which enables in-depth explorations of martensite mechanics using micro-scale specimens. Here we present a systematic investigation of the orientation dependence of tetragonal crystals undergoing a uniaxial stress-driven Martensitic Transformation to the monoclinic phase, in single crystal zirconia pillars doped with yttria and titania. The Young’s modulus, Martensitic Transformation stress and Transformation strain are highly dependent on the crystallographic orientation, and generally align with expectations based on known tensor properties and Transformation crystallography. However, in some orientations, fracture or plastic slip are apparently preferred to Martensitic Transformation, and thus crystallography favors certain orientations if superelasticity or shape memory properties are specifically desired in zirconia ceramics.
L Francis R Rose - One of the best experts on this subject based on the ideXlab platform.
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the Martensitic Transformation in ceramics its role in Transformation toughening
Progress in Materials Science, 2002Co-Authors: Patrick M. Kelly, L Francis R RoseAbstract:This paper reviews the current knowledge and understanding of Martensitic Transformations in ceramics - the tetragonal to monoclinic Transformation in zirconia in particular. This Martensitic Transformation is the key to Transformation toughening in zirconia ceramics. A very considerable body of experimental data on the characteristics of this Transformation is now available. In addition, theoretical predictions can be made using the phenomenological theory of Martensitic Transformations. As the paper will illustrate, the phenomenological theory is capable of explaining all the reported microstructural and crystallographic features of the Transformation in zirconia and in some other ceramic systems. Hence the theory, supported by experiment, can be used with considerable confidence to provide the quantitative data that is essential for developing a credible, comprehensive understanding of the Transformation toughening process. A critical feature in Transformation toughening is the shape strain that accompanies the Transformation. This shape strain, or nucleation strain, determines whether or not the stress-induced Martensitic Transformation can occur at the tip of a potentially dangerous crack. If Transformation does take place, then it is the net Transformation strain left behind in the transformed region that provides toughening by hindering crack growth. The fracture mechanics based models for Transformation toughening, therefore, depend on having a full understanding of the characteristics of the Martensitic Transformation and, in particular, on being able to specify both these strains. A review of the development of the models for Transformation toughening shows that their refinement and improvement over the last couple of decades has been largely a result of the inclusion of more of the characteristics of the stress-induced Martensitic Transformation. The paper advances an improved model for the stress-induced Martensitic Transformation and the strains resulting from the Transformation. This model, which separates the nucleation strain from the subsequent net Transformation strain, is shown to be superior to any of the constitutive models currently available. (C) 2002 Elsevier Science Ltd. All rights reserved.
