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Claudia Felser - One of the best experts on this subject based on the ideXlab platform.
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robust bain distortion in the premartensite Phase of a platinum substituted ni2mnga magnetic shape memory alloy
Nature Communications, 2017Co-Authors: Sanjay Kumar Singh, Biswanath Dutta, S W Dsouza, M G Zavareh, P Devi, Alexandra S Gibbs, Tilmann Hickel, Stanislav Chadov, Claudia FelserAbstract:The premartensite Phase of shape memory and magnetic shape memory alloys (MSMAs) is believed to be a precursor state of the martensite Phase with preserved Austenite Phase symmetry. The thermodynamic stability of the premartensite Phase and its relation to the martensitic Phase is still an unresolved issue, even though it is critical to the understanding of the functional properties of MSMAs. We present here unambiguous evidence for macroscopic symmetry breaking leading to robust Bain distortion in the premartensite Phase of 10% Pt-substituted Ni2MnGa. We show that the robust Bain-distorted premartensite (T2) Phase results from another premartensite (T1) Phase with preserved cubic-like symmetry through an isostructural Phase transition. The T2 Phase finally transforms to the martensite Phase with additional Bain distortion on further cooling. Our results demonstrate that the premartensite Phase should not be considered as a precursor state with the preserved symmetry of the cubic Austenite Phase.
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robust bain distortion in the premartensite Phase of a platinum substituted ni2mnga magnetic shape memory alloy
Nature Communications, 2017Co-Authors: Sanjay Kumar Singh, Biswanath Dutta, S W Dsouza, M G Zavareh, P Devi, Alexandra S Gibbs, Tilmann Hickel, Stanislav Chadov, Claudia FelserAbstract:The premartensite Phase of shape memory and magnetic shape memory alloys (MSMAs) is believed to be a precursor state of the martensite Phase with preserved Austenite Phase symmetry. The thermodynamic stability of the premartensite Phase and its relation to the martensitic Phase is still an unresolved issue, even though it is critical to the understanding of the functional properties of MSMAs. We present here unambiguous evidence for macroscopic symmetry breaking leading to robust Bain distortion in the premartensite Phase of 10% Pt-substituted Ni2MnGa. We show that the robust Bain-distorted premartensite (T2) Phase results from another premartensite (T1) Phase with preserved cubic-like symmetry through an isostructural Phase transition. The T2 Phase finally transforms to the martensite Phase with additional Bain distortion on further cooling. Our results demonstrate that the premartensite Phase should not be considered as a precursor state with the preserved symmetry of the cubic Austenite Phase. In magnetic shape memory Heusler alloys, the premartensite Phase is believed to be a precursor state of the martensite Phase with preserved Austenite Phase symmetry. Here, the authors show that the premartensite is a stable Phase with its own crystallographic symmetry resulting from the stepped growth of Bain distortions in the lattice.
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large field induced irreversibility in ni mn based heusler shape memory alloys a pulsed magnetic field study
Physical Review B, 2014Co-Authors: Ajaya K Nayak, Claudia Felser, S W Dsouza, Stanislav Chadov, Salazar C Mejia, Y Skourski, M NicklasAbstract:We present a pulsed magnetic field study on the magnetic and magnetostriction properties of Ni-Mn-Z (Z = In, Sn, and Sb) based Heusler shape-memory alloys. These materials generally display a field-induced magnetostructural transition that could lead to an irreversible Phase transition, when measured near the martensitic transition temperature. Here, we show that independently of the transition temperature, the critical field for the Phase transition sensitively depends on the main-group element in the sample. Irrespective of their compositions, all samples display a magnetization of around 2μB /f.u. in the martensite Phase and about 6μB /f.u. in the cubic Austenite Phase. Our magnetic and magnetostriction measurements at low temperatures exhibit a partial or complete arrest of the high-field Austenite Phase below the reverse martensitic transition. This results in a large irreversibility with a hysteresis width as high as 24 T. We introduce a theoretical model to discuss the experimental results.
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exploring the details of the martensite Austenite Phase transition of the shape memory heusler compound mn2niga by hard x ray photoelectron spectroscopy magnetic and transport measurements
Applied Physics Letters, 2011Co-Authors: Christian G F Blum, Siham Ouardi, Gerhard H Fecher, Benjamin Balke, Xeniya Kozina, G Stryganyuk, Shigenori Ueda, Keisuke Kobayashi, Claudia Felser, Sabine WurmehlAbstract:Mn2NiGa is reported to be a shape memory material with a martensite–Austenite Phase transition. Temperature dependent measurements of the transport and magnetic properties reveal the martensitic transition close to room temperature with a thermal hysteresis of about 27 K. The electronic structure of the valence band in both Phases was studied by hard x-ray photoelectron spectroscopy. The results clearly indicate that strong changes in the electronic structure appear at the Phase transition.
Sanjay Kumar Singh - One of the best experts on this subject based on the ideXlab platform.
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robust bain distortion in the premartensite Phase of a platinum substituted ni2mnga magnetic shape memory alloy
Nature Communications, 2017Co-Authors: Sanjay Kumar Singh, Biswanath Dutta, S W Dsouza, M G Zavareh, P Devi, Alexandra S Gibbs, Tilmann Hickel, Stanislav Chadov, Claudia FelserAbstract:The premartensite Phase of shape memory and magnetic shape memory alloys (MSMAs) is believed to be a precursor state of the martensite Phase with preserved Austenite Phase symmetry. The thermodynamic stability of the premartensite Phase and its relation to the martensitic Phase is still an unresolved issue, even though it is critical to the understanding of the functional properties of MSMAs. We present here unambiguous evidence for macroscopic symmetry breaking leading to robust Bain distortion in the premartensite Phase of 10% Pt-substituted Ni2MnGa. We show that the robust Bain-distorted premartensite (T2) Phase results from another premartensite (T1) Phase with preserved cubic-like symmetry through an isostructural Phase transition. The T2 Phase finally transforms to the martensite Phase with additional Bain distortion on further cooling. Our results demonstrate that the premartensite Phase should not be considered as a precursor state with the preserved symmetry of the cubic Austenite Phase. In magnetic shape memory Heusler alloys, the premartensite Phase is believed to be a precursor state of the martensite Phase with preserved Austenite Phase symmetry. Here, the authors show that the premartensite is a stable Phase with its own crystallographic symmetry resulting from the stepped growth of Bain distortions in the lattice.
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robust bain distortion in the premartensite Phase of a platinum substituted ni2mnga magnetic shape memory alloy
Nature Communications, 2017Co-Authors: Sanjay Kumar Singh, Biswanath Dutta, S W Dsouza, M G Zavareh, P Devi, Alexandra S Gibbs, Tilmann Hickel, Stanislav Chadov, Claudia FelserAbstract:The premartensite Phase of shape memory and magnetic shape memory alloys (MSMAs) is believed to be a precursor state of the martensite Phase with preserved Austenite Phase symmetry. The thermodynamic stability of the premartensite Phase and its relation to the martensitic Phase is still an unresolved issue, even though it is critical to the understanding of the functional properties of MSMAs. We present here unambiguous evidence for macroscopic symmetry breaking leading to robust Bain distortion in the premartensite Phase of 10% Pt-substituted Ni2MnGa. We show that the robust Bain-distorted premartensite (T2) Phase results from another premartensite (T1) Phase with preserved cubic-like symmetry through an isostructural Phase transition. The T2 Phase finally transforms to the martensite Phase with additional Bain distortion on further cooling. Our results demonstrate that the premartensite Phase should not be considered as a precursor state with the preserved symmetry of the cubic Austenite Phase.
S W Dsouza - One of the best experts on this subject based on the ideXlab platform.
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robust bain distortion in the premartensite Phase of a platinum substituted ni2mnga magnetic shape memory alloy
Nature Communications, 2017Co-Authors: Sanjay Kumar Singh, Biswanath Dutta, S W Dsouza, M G Zavareh, P Devi, Alexandra S Gibbs, Tilmann Hickel, Stanislav Chadov, Claudia FelserAbstract:The premartensite Phase of shape memory and magnetic shape memory alloys (MSMAs) is believed to be a precursor state of the martensite Phase with preserved Austenite Phase symmetry. The thermodynamic stability of the premartensite Phase and its relation to the martensitic Phase is still an unresolved issue, even though it is critical to the understanding of the functional properties of MSMAs. We present here unambiguous evidence for macroscopic symmetry breaking leading to robust Bain distortion in the premartensite Phase of 10% Pt-substituted Ni2MnGa. We show that the robust Bain-distorted premartensite (T2) Phase results from another premartensite (T1) Phase with preserved cubic-like symmetry through an isostructural Phase transition. The T2 Phase finally transforms to the martensite Phase with additional Bain distortion on further cooling. Our results demonstrate that the premartensite Phase should not be considered as a precursor state with the preserved symmetry of the cubic Austenite Phase. In magnetic shape memory Heusler alloys, the premartensite Phase is believed to be a precursor state of the martensite Phase with preserved Austenite Phase symmetry. Here, the authors show that the premartensite is a stable Phase with its own crystallographic symmetry resulting from the stepped growth of Bain distortions in the lattice.
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robust bain distortion in the premartensite Phase of a platinum substituted ni2mnga magnetic shape memory alloy
Nature Communications, 2017Co-Authors: Sanjay Kumar Singh, Biswanath Dutta, S W Dsouza, M G Zavareh, P Devi, Alexandra S Gibbs, Tilmann Hickel, Stanislav Chadov, Claudia FelserAbstract:The premartensite Phase of shape memory and magnetic shape memory alloys (MSMAs) is believed to be a precursor state of the martensite Phase with preserved Austenite Phase symmetry. The thermodynamic stability of the premartensite Phase and its relation to the martensitic Phase is still an unresolved issue, even though it is critical to the understanding of the functional properties of MSMAs. We present here unambiguous evidence for macroscopic symmetry breaking leading to robust Bain distortion in the premartensite Phase of 10% Pt-substituted Ni2MnGa. We show that the robust Bain-distorted premartensite (T2) Phase results from another premartensite (T1) Phase with preserved cubic-like symmetry through an isostructural Phase transition. The T2 Phase finally transforms to the martensite Phase with additional Bain distortion on further cooling. Our results demonstrate that the premartensite Phase should not be considered as a precursor state with the preserved symmetry of the cubic Austenite Phase.
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large field induced irreversibility in ni mn based heusler shape memory alloys a pulsed magnetic field study
Physical Review B, 2014Co-Authors: Ajaya K Nayak, Claudia Felser, S W Dsouza, Stanislav Chadov, Salazar C Mejia, Y Skourski, M NicklasAbstract:We present a pulsed magnetic field study on the magnetic and magnetostriction properties of Ni-Mn-Z (Z = In, Sn, and Sb) based Heusler shape-memory alloys. These materials generally display a field-induced magnetostructural transition that could lead to an irreversible Phase transition, when measured near the martensitic transition temperature. Here, we show that independently of the transition temperature, the critical field for the Phase transition sensitively depends on the main-group element in the sample. Irrespective of their compositions, all samples display a magnetization of around 2μB /f.u. in the martensite Phase and about 6μB /f.u. in the cubic Austenite Phase. Our magnetic and magnetostriction measurements at low temperatures exhibit a partial or complete arrest of the high-field Austenite Phase below the reverse martensitic transition. This results in a large irreversibility with a hysteresis width as high as 24 T. We introduce a theoretical model to discuss the experimental results.
Stanislav Chadov - One of the best experts on this subject based on the ideXlab platform.
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robust bain distortion in the premartensite Phase of a platinum substituted ni2mnga magnetic shape memory alloy
Nature Communications, 2017Co-Authors: Sanjay Kumar Singh, Biswanath Dutta, S W Dsouza, M G Zavareh, P Devi, Alexandra S Gibbs, Tilmann Hickel, Stanislav Chadov, Claudia FelserAbstract:The premartensite Phase of shape memory and magnetic shape memory alloys (MSMAs) is believed to be a precursor state of the martensite Phase with preserved Austenite Phase symmetry. The thermodynamic stability of the premartensite Phase and its relation to the martensitic Phase is still an unresolved issue, even though it is critical to the understanding of the functional properties of MSMAs. We present here unambiguous evidence for macroscopic symmetry breaking leading to robust Bain distortion in the premartensite Phase of 10% Pt-substituted Ni2MnGa. We show that the robust Bain-distorted premartensite (T2) Phase results from another premartensite (T1) Phase with preserved cubic-like symmetry through an isostructural Phase transition. The T2 Phase finally transforms to the martensite Phase with additional Bain distortion on further cooling. Our results demonstrate that the premartensite Phase should not be considered as a precursor state with the preserved symmetry of the cubic Austenite Phase. In magnetic shape memory Heusler alloys, the premartensite Phase is believed to be a precursor state of the martensite Phase with preserved Austenite Phase symmetry. Here, the authors show that the premartensite is a stable Phase with its own crystallographic symmetry resulting from the stepped growth of Bain distortions in the lattice.
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robust bain distortion in the premartensite Phase of a platinum substituted ni2mnga magnetic shape memory alloy
Nature Communications, 2017Co-Authors: Sanjay Kumar Singh, Biswanath Dutta, S W Dsouza, M G Zavareh, P Devi, Alexandra S Gibbs, Tilmann Hickel, Stanislav Chadov, Claudia FelserAbstract:The premartensite Phase of shape memory and magnetic shape memory alloys (MSMAs) is believed to be a precursor state of the martensite Phase with preserved Austenite Phase symmetry. The thermodynamic stability of the premartensite Phase and its relation to the martensitic Phase is still an unresolved issue, even though it is critical to the understanding of the functional properties of MSMAs. We present here unambiguous evidence for macroscopic symmetry breaking leading to robust Bain distortion in the premartensite Phase of 10% Pt-substituted Ni2MnGa. We show that the robust Bain-distorted premartensite (T2) Phase results from another premartensite (T1) Phase with preserved cubic-like symmetry through an isostructural Phase transition. The T2 Phase finally transforms to the martensite Phase with additional Bain distortion on further cooling. Our results demonstrate that the premartensite Phase should not be considered as a precursor state with the preserved symmetry of the cubic Austenite Phase.
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large field induced irreversibility in ni mn based heusler shape memory alloys a pulsed magnetic field study
Physical Review B, 2014Co-Authors: Ajaya K Nayak, Claudia Felser, S W Dsouza, Stanislav Chadov, Salazar C Mejia, Y Skourski, M NicklasAbstract:We present a pulsed magnetic field study on the magnetic and magnetostriction properties of Ni-Mn-Z (Z = In, Sn, and Sb) based Heusler shape-memory alloys. These materials generally display a field-induced magnetostructural transition that could lead to an irreversible Phase transition, when measured near the martensitic transition temperature. Here, we show that independently of the transition temperature, the critical field for the Phase transition sensitively depends on the main-group element in the sample. Irrespective of their compositions, all samples display a magnetization of around 2μB /f.u. in the martensite Phase and about 6μB /f.u. in the cubic Austenite Phase. Our magnetic and magnetostriction measurements at low temperatures exhibit a partial or complete arrest of the high-field Austenite Phase below the reverse martensitic transition. This results in a large irreversibility with a hysteresis width as high as 24 T. We introduce a theoretical model to discuss the experimental results.
T Kanomata - One of the best experts on this subject based on the ideXlab platform.
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observation of inverse magnetocaloric effect in magnetic field induced Austenite Phase of heusler alloys ni 50 x co x mn 31 5 ga 18 5 x 9 and 9 7
Physical Review Materials, 2021Co-Authors: Takumi Kihara, Tufan Roy, A Miyake, Masahito Tsujikawa, H Mitamura, Masashi Tokunaga, Y Adachi, T Eto, T KanomataAbstract:The magnetocaloric effect (MCE), magnetization, specific heat, and magnetostriction measurements were performed in both pulsed and steady high magnetic fields to investigate the magnetocaloric properties of Heusler alloys ${\mathrm{Ni}}_{50\ensuremath{-}x}{\mathrm{Co}}_{x}{\mathrm{Mn}}_{31.5}{\mathrm{Ga}}_{18.5}$ $(x=9 \mathrm{and} 9.7)$. From direct MCE measurements for ${\mathrm{Ni}}_{41}{\mathrm{Co}}_{9}{\mathrm{Mn}}_{31.5}{\mathrm{Ga}}_{18.5}$ up to 56 T, a steep temperature drop was observed for magnetic-field-induced martensitic transformation (MFIMT), designated as inverse MCE. Remarkably, this inverse MCE is apparent not only with MFIMT, but also in the magnetic-field-induced Austenite Phase. Specific heat measurements under steady high magnetic fields revealed that the magnetic field variation of the electronic entropy plays a dominant role in the unconventional magnetocaloric properties of these materials. First-principles based calculations performed for ${\mathrm{Ni}}_{41}{\mathrm{Co}}_{9}{\mathrm{Mn}}_{31.5}{\mathrm{Ga}}_{18.5}$ and ${\mathrm{Ni}}_{45}{\mathrm{Co}}_{5}{\mathrm{Mn}}_{36.7}{\mathrm{In}}_{13.3}$ revealed that the magnetic-field-induced Austenite Phase of ${\mathrm{Ni}}_{41}{\mathrm{Co}}_{9}{\mathrm{Mn}}_{31.5}{\mathrm{Ga}}_{18.5}$ is more unstable than that of ${\mathrm{Ni}}_{45}{\mathrm{Co}}_{5}{\mathrm{Mn}}_{36.7}{\mathrm{In}}_{13.3}$ and that it is sensitive to slight tetragonal distortion. We conclude that the inverse MCE in the magnetic-field-induced Austenite Phase is realized by marked change in the electronic entropy through tetragonal distortion induced by the externally applied magnetic field.
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observation of inverse magnetocaloric effect in magnetic field induced Austenite Phase of heusler alloys ni50 xcoxmn31 5ga18 5 x 9 and 9 7
arXiv: Materials Science, 2021Co-Authors: Takumi Kihara, Tufan Roy, A Miyake, Masahito Tsujikawa, H Mitamura, Masashi Tokunaga, Y Adachi, T Eto, T KanomataAbstract:Magnetocaloric effect (MCE), magnetization, specific heat, and magnetostriction measurements were performed in both pulsed and steady high magnetic fields to investigate the magnetocaloric properties of Heusler alloys Ni50-xCoxMn31.5Ga18.5 (x = 9 and 9.7). From direct MCE measurements for Ni41Co9Mn31.5Ga18.5 up to 56 T, a steep temperature drop was observed for magnetic-field-induced martensitic transformation (MFIMT), designated as inverse MCE. Remarkably, this inverse MCE is apparent not only with MFIMT, but also in the magnetic-field-induced Austenite Phase. Specific heat measurements under steady high magnetic fields revealed that the magnetic field variation of the electronic entropy plays a dominant role in the unconventional magnetocaloric properties of these materials. First-principles based calculations performed for Ni41Co9Mn31.5Ga18.5 and Ni45Co5Mn36.7In13.3 revealed that the magnetic-field-induced Austenite Phase of Ni41Co9Mn31.5Ga18.5 is more unstable than that of Ni45Co5Mn36.7In13.3 and that it is sensitive to slight tetragonal distortion. We conclude that the inverse MCE in the magnetic-field-induced Austenite Phase is realized by marked change in the electronic entropy through tetragonal distortion induced by the externally applied magnetic field.
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effect of magnetic field on martensitic transition of ni46mn41in13 heusler alloy
Applied Physics Letters, 2006Co-Authors: K Oikawa, Y Imano, Y Sutou, R Kainuma, K Ishida, S Okamoto, O Kitakami, T KanomataAbstract:Magnetic and martensitic transition behaviors of a Ni46Mn41In13 Heusler alloy were investigated by differential scanning calorimetry and vibrating sample magnetometry. A unique martensitic transition from the ferromagnetic Austenite Phase to the antiferromagneticlike martensite Phase was detected and magnetic-field-induced “reverse” transition was confirmed in a high magnetic field. In addition, a large positive magnetic entropy change, which reached 13J∕kgK at 9T, was observed to accompany reverse martensitic transition. This alloy shows promise as a metamagnetic shape memory alloy with magnetic-field-induced shape memory effect and as a magnetocaloric material.
