title: (3 + 1)D superspace description of the incommensurate modulation in the premartensite phase of Ni2MnGa: a high resolution synchrotron x-ray powder diffraction study.
abstract: Le Bail and Rietveld analysis of high resolution synchrotron x-ray powder diffraction (SXRPD) data shows unambiguous signatures of the failure of the commensurate 3M modulation model. Using (3 + 1) dimensional superspace group formalism, we have not only confirmed the incommensurate modulation in the premartensite phase with a modulation wavevector of q = 0.337 61(5)c* but also determined the superspace group (Immm(00γ)s00), atomic positions and amplitude of modulations for the incommensurate premartensite phase of Ni2MnGa for the first time. Our results may have important implications in the understanding of the martensitic transition and hence the magnetic field induced strains.
authors: UGC-DAE Consortium for Scientific Research, Indore, India.
authors: Sanjay
authors: S
authors: Singh
authors: J
authors: J
authors: Nayak
authors: Abhishek
authors: A
authors: Rai
authors: Parasmani
authors: P
authors: Rajput
authors: Adrian H
authors: AH
authors: Hill
authors: S R
authors: SR
authors: Barman
authors: Dhananjai
authors: D
authors: Pandey