UGC-DAE Consortium for Scientific Research, Indore, India.
J Phys Condens Matter. 2013 May 29;25(21):212203. doi: 10.1088/0953-8984/25/21/212203. Epub 2013 May 9.
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.
高分辨率同步加速器 X 射线粉末衍射（SXRPD）数据的 Le Bail 和 Rietveld 分析显示，相位匹配 3M 调制模型的失败具有明确的特征。我们使用（3+1）维超空间群形式，不仅证实了前马氏体相中具有调制波矢 q = 0.33761(5)c*的非相位匹配调制，而且首次确定了 Ni2MnGa 非相位匹配前马氏体相的超空间群（Immm(00γ)s00）、原子位置和调制幅度。我们的结果可能对理解马氏体相变以及磁场诱导应变具有重要意义。
