Crystal structure of orthorhombic martensite in TiNi-Cu and TiNi-Pd intermetallics
Crystal structure of orthorhombic martensite in TiNi-Cu and TiNi-Pd intermetallics
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DOI：
10.1051/jp4:2003985
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发表时间：
2003-10-01
期刊：
影响因子：
--
通讯作者：
Schryvers, D
中科院分区：
文献类型：
--
作者：
Potapov, PL;Kulkova, SE;Schryvers, D
三元镍基化合物中正交马氏体的晶体结构已被多次研究，尽管在所有情况下，由于原子在单位胞中的位置仍然未知，结构尚未完全解决。在本工作中，用Rietveld方法对Ti - cu和Ti - pd薄膜的x射线图进行了细化，揭示了Ti和Ni原子位置的重要规律。特别是在正交马氏体结构中，（010）原子面总是扭曲的，并且平面对称中心松散。这一观察结果被从头算证实，原子位置的变化是为了最小化电子能带的能量。
The crystal structure of orthorhombic martensite in ternary TiNi-based compounds has been several times examined, although, in all cases, the structure was not completely solved as the positions of atoms in the unit cell remained unknown. In the present work, the X-ray patterns of TiNi-Cu and TiNi-Pd films were refined by the Rietveld method revealing important regularities in the location of Ti and Ni atoms. In particular, the (010) atomic planes in the orthorhombic martensite structure are always distorted and loose the planar centre of symmetry. This observation was confirmed by ab-initio calculations, where the atomic positions were varied in order to minimise the energy of electron bands.