The Experts below are selected from a list of 273 Experts worldwide ranked by ideXlab platform
Minoru Nishida - One of the best experts on this subject based on the ideXlab platform.
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crystallography and morphology of Antiphase Boundary like structure induced by martensitic transformation in ti pd fe alloy
Journal of Alloys and Compounds, 2015Co-Authors: Mitsuhiro Matsuda, Sadahiro Tsurekawa, Kazuki Takashima, Masatoshi Mitsuhara, S Nishimura, Minoru NishidaAbstract:Abstract The Antiphase Boundary (APB)-like structure of both 9R and B19 martensites in the Ti–Pd–Fe alloy was investigated by means of transmission electron microscopy. Some APB-like structures with curved and wide contrasts along the (0 0 1) 9R basal plane are observed in 9R martensitic plates. The atomic displacement on the APB-like structure reflects the atomic movement stemming from the microdomains formed as a pre-martensitic transformation. The displacement vector of the APB-like structure in the B19 martensite can be expressed as R = 〈1/3 0 −1/2〉 B19 . The density of APB-like contrasts increases by the substitution of Fe for Pd in Ti–Pd–Fe alloy.
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Antiphase Boundary like structure of b19 martensite via r phase transformation in ti ni fe alloy
Journal of Alloys and Compounds, 2014Co-Authors: Mitsuhiro Matsuda, R Yamashita, Sadahiro Tsurekawa, Kazuki Takashima, Masatoshi Mitsuhara, Minoru NishidaAbstract:Abstract The Antiphase Boundary (APB)-like structure of B19′ martensite via R-phase transformation in a Ti–Ni–Fe alloy was investigated by means of transmission electron microscopy. The APB-like structure exhibited shifts along the (0 1 0) B19 ′ , (0 0 1) B19 ′ , and (1 0 0) B19 ′ planes; that is, it exhibited facets composed of those planes at the atomic level. This atomic displacement reflects the atomic movement stemming from the R-phase transformation.
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transmission electron microscopy of Antiphase Boundary like structure of b19 martensite in ti ni shape memory alloy
Acta Materialia, 2011Co-Authors: Mitsuhiro Matsuda, Sadahiro Tsurekawa, Toru Hara, E Okunishi, K Kuramoto, Yasuhiro Morizono, Minoru NishidaAbstract:Abstract An Antiphase Boundary (APB)-like structure of the B19′ martensite in Ti–Ni alloy was investigated by transmission electron microscopy. The APB-like structure shows atomic shifts on both the (0 1 0)B19′ plane along the c-axis and the (0 0 1)B19′ plane along the b-axis; a kind of ledge-and-step structure on the b–c plane, in addition to a displacement along the a-axis. The displacement vector can be expressed as R = 〈−0.1648 1/2 0.4328〉 in terms of the conventional atomic coordinates of Ti and Ni in the B19′ martensite. The APB-like structure is not inherited from APB in the B2 parent phase. We conclude that the APB-like structure is developed by accidental impingement of differently nucleated martensitic domains during the transformation. This structure is defined as a kind of stacking fault with an APB-like contrast.
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high angle annular dark field scanning transmission electron microscopy of the Antiphase Boundary in a rapidly solidified b2 type tipd compound
Philosophical Magazine Letters, 2007Co-Authors: Mitsuhiro Matsuda, Toru Hara, E Okunishi, Minoru NishidaAbstract:High-angle annular dark field scanning transmission electron microscopy (HAADF-STEM) with Z-contrast is applied to characterize the Antiphase Boundary (APB) of the B2 structure in a rapidly solidified TiPd melt-spun compound. The atomic shift associated with the R = (1/2) a 0 ⟨111⟩ type displacement vector is directly observed at the Boundary. A microstructure modification of the melt-spun compound with the cooling rate during solidification is also described.
Mitsuhiro Matsuda - One of the best experts on this subject based on the ideXlab platform.
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crystallography and morphology of Antiphase Boundary like structure induced by martensitic transformation in ti pd fe alloy
Journal of Alloys and Compounds, 2015Co-Authors: Mitsuhiro Matsuda, Sadahiro Tsurekawa, Kazuki Takashima, Masatoshi Mitsuhara, S Nishimura, Minoru NishidaAbstract:Abstract The Antiphase Boundary (APB)-like structure of both 9R and B19 martensites in the Ti–Pd–Fe alloy was investigated by means of transmission electron microscopy. Some APB-like structures with curved and wide contrasts along the (0 0 1) 9R basal plane are observed in 9R martensitic plates. The atomic displacement on the APB-like structure reflects the atomic movement stemming from the microdomains formed as a pre-martensitic transformation. The displacement vector of the APB-like structure in the B19 martensite can be expressed as R = 〈1/3 0 −1/2〉 B19 . The density of APB-like contrasts increases by the substitution of Fe for Pd in Ti–Pd–Fe alloy.
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Antiphase Boundary like structure of b19 martensite via r phase transformation in ti ni fe alloy
Journal of Alloys and Compounds, 2014Co-Authors: Mitsuhiro Matsuda, R Yamashita, Sadahiro Tsurekawa, Kazuki Takashima, Masatoshi Mitsuhara, Minoru NishidaAbstract:Abstract The Antiphase Boundary (APB)-like structure of B19′ martensite via R-phase transformation in a Ti–Ni–Fe alloy was investigated by means of transmission electron microscopy. The APB-like structure exhibited shifts along the (0 1 0) B19 ′ , (0 0 1) B19 ′ , and (1 0 0) B19 ′ planes; that is, it exhibited facets composed of those planes at the atomic level. This atomic displacement reflects the atomic movement stemming from the R-phase transformation.
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transmission electron microscopy of Antiphase Boundary like structure of b19 martensite in ti ni shape memory alloy
Acta Materialia, 2011Co-Authors: Mitsuhiro Matsuda, Sadahiro Tsurekawa, Toru Hara, E Okunishi, K Kuramoto, Yasuhiro Morizono, Minoru NishidaAbstract:Abstract An Antiphase Boundary (APB)-like structure of the B19′ martensite in Ti–Ni alloy was investigated by transmission electron microscopy. The APB-like structure shows atomic shifts on both the (0 1 0)B19′ plane along the c-axis and the (0 0 1)B19′ plane along the b-axis; a kind of ledge-and-step structure on the b–c plane, in addition to a displacement along the a-axis. The displacement vector can be expressed as R = 〈−0.1648 1/2 0.4328〉 in terms of the conventional atomic coordinates of Ti and Ni in the B19′ martensite. The APB-like structure is not inherited from APB in the B2 parent phase. We conclude that the APB-like structure is developed by accidental impingement of differently nucleated martensitic domains during the transformation. This structure is defined as a kind of stacking fault with an APB-like contrast.
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high angle annular dark field scanning transmission electron microscopy of the Antiphase Boundary in a rapidly solidified b2 type tipd compound
Philosophical Magazine Letters, 2007Co-Authors: Mitsuhiro Matsuda, Toru Hara, E Okunishi, Minoru NishidaAbstract:High-angle annular dark field scanning transmission electron microscopy (HAADF-STEM) with Z-contrast is applied to characterize the Antiphase Boundary (APB) of the B2 structure in a rapidly solidified TiPd melt-spun compound. The atomic shift associated with the R = (1/2) a 0 ⟨111⟩ type displacement vector is directly observed at the Boundary. A microstructure modification of the melt-spun compound with the cooling rate during solidification is also described.
Sadahiro Tsurekawa - One of the best experts on this subject based on the ideXlab platform.
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crystallography and morphology of Antiphase Boundary like structure induced by martensitic transformation in ti pd fe alloy
Journal of Alloys and Compounds, 2015Co-Authors: Mitsuhiro Matsuda, Sadahiro Tsurekawa, Kazuki Takashima, Masatoshi Mitsuhara, S Nishimura, Minoru NishidaAbstract:Abstract The Antiphase Boundary (APB)-like structure of both 9R and B19 martensites in the Ti–Pd–Fe alloy was investigated by means of transmission electron microscopy. Some APB-like structures with curved and wide contrasts along the (0 0 1) 9R basal plane are observed in 9R martensitic plates. The atomic displacement on the APB-like structure reflects the atomic movement stemming from the microdomains formed as a pre-martensitic transformation. The displacement vector of the APB-like structure in the B19 martensite can be expressed as R = 〈1/3 0 −1/2〉 B19 . The density of APB-like contrasts increases by the substitution of Fe for Pd in Ti–Pd–Fe alloy.
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Antiphase Boundary like structure of b19 martensite via r phase transformation in ti ni fe alloy
Journal of Alloys and Compounds, 2014Co-Authors: Mitsuhiro Matsuda, R Yamashita, Sadahiro Tsurekawa, Kazuki Takashima, Masatoshi Mitsuhara, Minoru NishidaAbstract:Abstract The Antiphase Boundary (APB)-like structure of B19′ martensite via R-phase transformation in a Ti–Ni–Fe alloy was investigated by means of transmission electron microscopy. The APB-like structure exhibited shifts along the (0 1 0) B19 ′ , (0 0 1) B19 ′ , and (1 0 0) B19 ′ planes; that is, it exhibited facets composed of those planes at the atomic level. This atomic displacement reflects the atomic movement stemming from the R-phase transformation.
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transmission electron microscopy of Antiphase Boundary like structure of b19 martensite in ti ni shape memory alloy
Acta Materialia, 2011Co-Authors: Mitsuhiro Matsuda, Sadahiro Tsurekawa, Toru Hara, E Okunishi, K Kuramoto, Yasuhiro Morizono, Minoru NishidaAbstract:Abstract An Antiphase Boundary (APB)-like structure of the B19′ martensite in Ti–Ni alloy was investigated by transmission electron microscopy. The APB-like structure shows atomic shifts on both the (0 1 0)B19′ plane along the c-axis and the (0 0 1)B19′ plane along the b-axis; a kind of ledge-and-step structure on the b–c plane, in addition to a displacement along the a-axis. The displacement vector can be expressed as R = 〈−0.1648 1/2 0.4328〉 in terms of the conventional atomic coordinates of Ti and Ni in the B19′ martensite. The APB-like structure is not inherited from APB in the B2 parent phase. We conclude that the APB-like structure is developed by accidental impingement of differently nucleated martensitic domains during the transformation. This structure is defined as a kind of stacking fault with an APB-like contrast.
Y Q Sun - One of the best experts on this subject based on the ideXlab platform.
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the strain field and work hardening from Antiphase Boundary tubes in ordered alloys
Materials Science and Engineering A-structural Materials Properties Microstructure and Processing, 1992Co-Authors: P M Hazzledine, Y Q SunAbstract:Abstract The materials inside an Antiphase Boundary (APB) tube is shifted by half a lattice spacing along the axis of the tube; it is also compressed by the APB and, therefore, has the strain field of a line of dilatation. This strain field shears the surrounding material in plane strain. Tubes may be imaged in the electron microscope by any reflection vector except a fundamental vector parallel to the tubes. The stress field of a tube interacts strongly with some dislocations but not with the particular dislocations from which the tube could be formed. Tubes work-harden ordered alloys in a number of ways: (i) by dragging on primary edge dislocations, (ii) by modifying the cross-slip probabilities of primary screw dislocations, (iii) by direct stress field interaction with secondary coplanar dislocations and (iv) by acting as a forest to other secondary dislocations.
V K Lazarov - One of the best experts on this subject based on the ideXlab platform.
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the Antiphase Boundary in half metallic heusler alloy co2fe al si atomic structure spin polarization reversal and domain wall effects
Applied Physics Letters, 2016Co-Authors: Zlatko Nedelkoski, Ana M Sanchez, Arsham Ghasemi, K Hamaya, Richard F L Evans, Gavin R Bell, A Hirohata, V K LazarovAbstract:Atomic resolution scanning transmission electron microscopy reveals the presence of an Antiphase Boundary in the half-metallic Co2Fe(Al,Si) full Heusler alloy. By employing the density functional theory calculations, we show that this defect leads to reversal of the sign of the spin-polarization in the vicinity of the defect. In addition, we show that this defect reduces the strength of the exchange interactions, without changing the ferromagnetic ordering across the Boundary. Atomistic spin calculations predict that this effect reduces the width of the magnetic domain wall compared to that in the bulk.
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atomic scale structure and properties of highly stable Antiphase Boundary defects in fe 3 o 4
Nature Communications, 2014Co-Authors: Keith P. Mckenna, Florian Hofer, Daniel Gilks, Chunlin Chen, Zhongchang Wang, V K Lazarov, Yuichi IkuharaAbstract:The complex and intriguing properties of the ferrimagnetic half metal magnetite (Fe3O4) are of continuing fundamental interest as well as being important for practical applications in spintronics, magnetism, catalysis and medicine. There is considerable speculation concerning the role of the ubiquitous Antiphase Boundary (APB) defects in magnetite, however, direct information on their structure and properties has remained challenging to obtain. Here we combine predictive first principles modelling with high-resolution transmission electron microscopy to unambiguously determine the three-dimensional structure of APBs in magnetite. We demonstrate that APB defects on the {110} planes are unusually stable and induce antiferromagnetic coupling between adjacent domains providing an explanation for the magnetoresistance and reduced spin polarization often observed. We also demonstrate how the high stability of the {110} APB defects is connected to the existence of a metastable bulk phase of Fe3O4, which could be stabilized by strain in films or nanostructures.