Neutron Diffraction Study of the Martensitic Transformation of Ni<sub>2.07</sub>Mn<sub>0.93</sub>Ga Heusler Alloy

Neutron Diffraction Study of the Martensitic Transformation of Ni<sub>2.07</sub>Mn<sub>0.93</sub>Ga Heusler Alloy

The martensitic transition featuring the ternary Heusler alloy Ni2.09Mn0.91Ga was investigated by neutron diffraction. Differential scanning calorimetry indicated that structural transition starts at 230 K on cooling with a significant increase in the martensitic transformation onset compared to the...

Descripción completa

Guardado en:
Detalles Bibliográficos
Autor principal: Lara Righi
Formato: article
Lenguaje:EN
Publicado: MDPI AG 2021
Materias:
Heusler alloys
martensitic transformation
neutron diffraction
Mining engineering. Metallurgy
TN1-997
Acceso en línea:https://doaj.org/article/e37b0727b278418f8f86a04e9323282e
Etiquetas: Agregar Etiqueta
Sin Etiquetas, Sea el primero en etiquetar este registro!
id oai:doaj.org-article:e37b0727b278418f8f86a04e9323282e
record_format dspace
spelling oai:doaj.org-article:e37b0727b278418f8f86a04e9323282e2021-11-25T18:21:40ZNeutron Diffraction Study of the Martensitic Transformation of Ni<sub>2.07</sub>Mn<sub>0.93</sub>Ga Heusler Alloy10.3390/met111117492075-4701https://doaj.org/article/e37b0727b278418f8f86a04e9323282e2021-10-01T00:00:00Zhttps://www.mdpi.com/2075-4701/11/11/1749https://doaj.org/toc/2075-4701The martensitic transition featuring the ternary Heusler alloy Ni2.09Mn0.91Ga was investigated by neutron diffraction. Differential scanning calorimetry indicated that structural transition starts at 230 K on cooling with a significant increase in the martensitic transformation onset compared to the classical Ni2MnGa. The low-temperature martensite presents the 5M type of modulated structure, and the structural analysis was performed by the application of the superspace approach. As already observed in Mn-rich modulated martensites, the periodical distortion corresponds to an incommensurate wave-like shift of the atomic layers. The symmetry of the modulated martensite at 220 K is orthorhombic with unit cell constants <i>a</i> = 4.2172(3) Å, <i>b</i> = 5.5482(2) Å, and <i>c</i> = 4.1899(2) Å; space group Immm(00γ)s00; and modulation vector <i>q</i> = <i>γc</i>* = 0.4226(5)<i>c</i>*. Considering the different neutron scattering lengths of the elements involved in this alloy, it was possible to ascertain that the chemical composition was Ni2.07Mn0.93Ga, close to the nominal formula. In order to characterize the martensitic transformation upon increasing the temperature, a series of neutron diffraction patterns was collected at different temperatures. The structural analysis indicated that the progressive change of the martensitic lattice is characterized by the exponential change of the <i>c</i>/<i>a</i> parameter approaching the limit value <i>c</i>/<i>a</i> = 1 of the cubic austenite.Lara RighiMDPI AGarticleHeusler alloysmartensitic transformationneutron diffractionMining engineering. MetallurgyTN1-997ENMetals, Vol 11, Iss 1749, p 1749 (2021)
institution DOAJ
collection DOAJ
language EN
topic Heusler alloys
martensitic transformation
neutron diffraction
Mining engineering. Metallurgy
TN1-997
spellingShingle Heusler alloys
martensitic transformation
neutron diffraction
Mining engineering. Metallurgy
TN1-997
Lara Righi
Neutron Diffraction Study of the Martensitic Transformation of Ni<sub>2.07</sub>Mn<sub>0.93</sub>Ga Heusler Alloy
description The martensitic transition featuring the ternary Heusler alloy Ni2.09Mn0.91Ga was investigated by neutron diffraction. Differential scanning calorimetry indicated that structural transition starts at 230 K on cooling with a significant increase in the martensitic transformation onset compared to the classical Ni2MnGa. The low-temperature martensite presents the 5M type of modulated structure, and the structural analysis was performed by the application of the superspace approach. As already observed in Mn-rich modulated martensites, the periodical distortion corresponds to an incommensurate wave-like shift of the atomic layers. The symmetry of the modulated martensite at 220 K is orthorhombic with unit cell constants <i>a</i> = 4.2172(3) Å, <i>b</i> = 5.5482(2) Å, and <i>c</i> = 4.1899(2) Å; space group Immm(00γ)s00; and modulation vector <i>q</i> = <i>γc</i>* = 0.4226(5)<i>c</i>*. Considering the different neutron scattering lengths of the elements involved in this alloy, it was possible to ascertain that the chemical composition was Ni2.07Mn0.93Ga, close to the nominal formula. In order to characterize the martensitic transformation upon increasing the temperature, a series of neutron diffraction patterns was collected at different temperatures. The structural analysis indicated that the progressive change of the martensitic lattice is characterized by the exponential change of the <i>c</i>/<i>a</i> parameter approaching the limit value <i>c</i>/<i>a</i> = 1 of the cubic austenite.
format article
author Lara Righi
author_facet Lara Righi
author_sort Lara Righi
title Neutron Diffraction Study of the Martensitic Transformation of Ni<sub>2.07</sub>Mn<sub>0.93</sub>Ga Heusler Alloy
title_short Neutron Diffraction Study of the Martensitic Transformation of Ni<sub>2.07</sub>Mn<sub>0.93</sub>Ga Heusler Alloy
title_full Neutron Diffraction Study of the Martensitic Transformation of Ni<sub>2.07</sub>Mn<sub>0.93</sub>Ga Heusler Alloy
title_fullStr Neutron Diffraction Study of the Martensitic Transformation of Ni<sub>2.07</sub>Mn<sub>0.93</sub>Ga Heusler Alloy
title_full_unstemmed Neutron Diffraction Study of the Martensitic Transformation of Ni<sub>2.07</sub>Mn<sub>0.93</sub>Ga Heusler Alloy
title_sort neutron diffraction study of the martensitic transformation of ni<sub>2.07</sub>mn<sub>0.93</sub>ga heusler alloy
publisher MDPI AG
publishDate 2021
url https://doaj.org/article/e37b0727b278418f8f86a04e9323282e
work_keys_str_mv AT lararighi neutrondiffractionstudyofthemartensitictransformationofnisub207submnsub093subgaheusleralloy
_version_ 1718411291071086592

Ejemplares similares