Neutron diffraction study of a non-stoichiometric Ni-Mn-Ga MSM ALLOY

Tutkimustuotos: Lehtiartikkelivertaisarvioitu

Tutkijat

Organisaatiot

  • Western Michigan University
  • Oak Ridge National Laboratory
  • Russian Academy of Sciences

Kuvaus

The structure and chemical order of a Heusler alloy of non-stoichiometric composition Ni-Mn-Ga were studied using constant-wavelength (1.538 Å) neutron diffraction at 363K and the diffraction pattern was refined using the FullProf software. At this temperature the structure is austenite (cubic) with Fm-3m space group and lattice constant of a = 5.83913(4) [Å]. The chemical order is of critical importance in these alloys, as Mn becomes antiferromagnetic when the atoms are closer than the radius of the 3d shell. In the studied alloy the refinement of the site occupancy showed that the 4b (Ga site) contained as much as 22% Mn; that significantly alters the distances between the Mn atoms in the crystal and, as a result, also the exchange energy between some of the Mn atoms. Based on the refinement, the composition was determined to be Ni1.91Mn1.29Ga0.8.

Yksityiskohdat

AlkuperäiskieliEnglanti
Sivut103-107
Sivumäärä5
JulkaisuMaterials Science Forum
Vuosikerta738-739
TilaJulkaistu - tammikuuta 2013
OKM-julkaisutyyppiA1 Julkaistu artikkeli, soviteltu

ID: 4681808