Publication detail

Switching the soft shearing mode orientation in Ni-Mn-Ga non-modulated martensite by Co and Cu doping

BODNÁROVÁ, L. ZELENÝ, M. SEDLÁK, P. STRAKA, L. HECZKO, O. SOZINOV, A. SEINER, H

English title

Switching the soft shearing mode orientation in Ni-Mn-Ga non-modulated martensite by Co and Cu doping

Type

journal article in Web of Science

Language

en

Original abstract

Resonant ultrasound spectroscopy measurements and density functional theory calculations were used to analyze the effect of Co and Cu doping (3-6 at. %) on elastic constants of non-modulated martensite of the Ni-Mn-Ga ferromagnetic shape memory alloy. Due to the doping, the studied alloys exhibited decreased tetragonal ratios c/a..1.14. Both the experiments and the calculations revealed that the lowering of the c/a ratio resulted in a change of the orientation of the softest shearing modes of the tetragonal lattice. The newly appearing softest shearing modes for the doped materials have approximately {1 a 0 1 c} bcta-1 a 0 1 cnbct orientations and indicate a lattice instability directly related to the particularly low twinning stress for compound {101} a1 01n twins, needed for the magnetically induced reorientation.

English abstract

Resonant ultrasound spectroscopy measurements and density functional theory calculations were used to analyze the effect of Co and Cu doping (3-6 at. %) on elastic constants of non-modulated martensite of the Ni-Mn-Ga ferromagnetic shape memory alloy. Due to the doping, the studied alloys exhibited decreased tetragonal ratios c/a..1.14. Both the experiments and the calculations revealed that the lowering of the c/a ratio resulted in a change of the orientation of the softest shearing modes of the tetragonal lattice. The newly appearing softest shearing modes for the doped materials have approximately {1 a 0 1 c} bcta-1 a 0 1 cnbct orientations and indicate a lattice instability directly related to the particularly low twinning stress for compound {101} a1 01n twins, needed for the magnetically induced reorientation.

Keywords in English

magnetic shape memory; elastic constants; acoustic methods; ab initio calculations; resonant ultrasound spectroscopy

Released

09.03.2020

Publisher

IOP PUBLISHING LTD

Location

BRISTOL

ISSN

0964-1726

Volume

29

Number

4

Pages from–to

045022–-

Pages count

9

BIBTEX


@article{BUT163259,
  author="Martin {Zelený},
  title="Switching the soft shearing mode orientation in Ni-Mn-Ga non-modulated martensite by Co and Cu doping",
  year="2020",
  volume="29",
  number="4",
  month="March",
  pages="045022---",
  publisher="IOP PUBLISHING LTD",
  address="BRISTOL",
  issn="0964-1726"
}