Publication detail

The Effect of Local Arrangement of Excess Mn on Phase Stability in Ni-Mn-Ga Martensite: An Ab Initio Study

ZELENÝ, M. HECZKO, M. JANOVEC, J. HOLEC, D. STRAKA, L. HECZKO, O.

English title

The Effect of Local Arrangement of Excess Mn on Phase Stability in Ni-Mn-Ga Martensite: An Ab Initio Study

Type

journal article in Web of Science

Language

en

Original abstract

The effect of excess Mn on the stability of modulation and elastic properties was investigated using ab initio electronic structure calculations in Ni-Mn-Ga magnetic shape memory alloy. We used the structure of four layered modulated martensite known as 4O to describe modulation of the martensitic lattice. We found that elastic properties of stoichiometric 4O martensite are very similar to elastic properties of 10M martensite reported in previous calculations. The modulated structure becomes less stable than nonmodulated martensite above 3 at.% of excess Mn which corresponds very well to experimental observation at low temperature. Elastic properties of NM martensite are not significantly affected by Mn content nor local arrangements of Mn-excess atoms. We also found that Mn-excess atoms prefer occupation of distant positions for low Mn-excess composition. The occupation of closest position is preferred for alloys with higher content of Mn.

English abstract

The effect of excess Mn on the stability of modulation and elastic properties was investigated using ab initio electronic structure calculations in Ni-Mn-Ga magnetic shape memory alloy. We used the structure of four layered modulated martensite known as 4O to describe modulation of the martensitic lattice. We found that elastic properties of stoichiometric 4O martensite are very similar to elastic properties of 10M martensite reported in previous calculations. The modulated structure becomes less stable than nonmodulated martensite above 3 at.% of excess Mn which corresponds very well to experimental observation at low temperature. Elastic properties of NM martensite are not significantly affected by Mn content nor local arrangements of Mn-excess atoms. We also found that Mn-excess atoms prefer occupation of distant positions for low Mn-excess composition. The occupation of closest position is preferred for alloys with higher content of Mn.

Keywords in English

Ni-Mn-Ga; Magnetic shape memory; Martensitic transformation; Elastic properties; Ab initio calculation

Released

01.03.2020

Publisher

SPRINGER INTERNATIONAL PUBLISHING AG

Location

CHAM

ISSN

2199-3858

Volume

6

Number

1

Pages from–to

35–44

Pages count

10

BIBTEX


@article{BUT162377,
  author="Martin {Zelený} and Martin {Heczko} and Jozef {Janovec} and David {Holec} and Ladislav {Straka} and Oleg {Heczko},
  title="The Effect of Local Arrangement of Excess Mn on Phase Stability in Ni-Mn-Ga Martensite: An Ab Initio Study",
  year="2020",
  volume="6",
  number="1",
  month="March",
  pages="35--44",
  publisher="SPRINGER INTERNATIONAL PUBLISHING AG",
  address="CHAM",
  issn="2199-3858"
}