High-resolution synchrotron x-ray powder diffraction study of the incommensurate modulation in the martensite phase of Ni.sub.2./sub.MnGa: Evidence for nearly 7M modulation and phason broadening

0436089 - FZÚ 2015 RIV US eng J - Článek v odborném periodiku
Singh, S. - Petříček, Václav - Rajput, P. - Hill, A.H. - Suard, E. - Barman, S.R. - Pandey, D.
High-resolution synchrotron x-ray powder diffraction study of the incommensurate modulation in the martensite phase of Ni₂MnGa: Evidence for nearly 7M modulation and phason broadening.
Physical Review. B. Roč. 90, č. 1 (2014), "014109-1"-"014109-9". ISSN 1098-0121
Institucionální podpora: RVO:68378271
Klíčová slova: modulated structure * superspace approach * rietveld refinement
Kód oboru RIV: BM - Fyzika pevných látek a magnetismus
Impakt faktor: 3.736, rok: 2014

The modulated structure of the martensite phase of Ni2MnGa is revisited using high-resolution synchrotron x-ray powder diffraction measurements, which reveal higher-order satellite reflections up to the third order and phason broadening of the satellite peaks. The structure refinement, using the (3+1) dimensional superspace group approach, shows that the modulated structure of Ni2MnGa can be described by orthorhombic superspace group Immm(00γ )s00 with lattice parameters a = 4.21861(2) A° , b = 5.54690(3) A° , and c = 4.18763(2) A° , and an incommensurate modulation wave vector q = 0.43160(3) c* = (3/7 + δ)c*, where δ = 0.00303(3) is the degree of incommensuration of the modulated structure.
Trvalý link: http://hdl.handle.net/11104/0239882