Fundamental structure of a Ni2MnGa intermediate phase having an orthorhombic lattice
Fundamental structure of a Ni2MnGa intermediate phase having an orthorhombic lattice
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DOI：
10.1088/0964-1726/14/5/004
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发表时间：
2005-10
影响因子：
4.1
通讯作者：
T. Ohba;N. Miyamoto;K. Fukuda;T. Fukuda;T. Kakeshita;K. Kato
中科院分区：
文献类型：
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作者：
T. Ohba;N. Miyamoto;K. Fukuda;T. Fukuda;T. Kakeshita;K. Kato
Ni_2MnGa是一种很有吸引力的铁磁形状记忆合金。据报道，母相是Heusler型的，并且转变成高于Ms的中间相。关于中间相的晶体结构，先前报道的是，fcc主反射保持不变，并且在冷却时出现额外的峰。这意味着长程有序结构是由立方基本晶格产生的。然而，我们成功地测量峰值分裂的基本反射从中间阶段使用高能量同步辐射。用全谱图分解法进行了仔细的分析，并提出了晶格常数a = 5.8285，B = 5.8142，c = 5.7886的正交基本晶格的明确证据。
Ni2MnGa is one of the attractive ferromagnetic shape memory alloys. It is reported that the parent phase is of Heusler type and transforms into an intermediate phase above Ms. As regards the crystal structure of the intermediate phase, it was previously reported that the fcc main reflection remained and additional peaks appeared on cooling. This means that the long range ordered structure was produced with a cubic fundamental lattice. However, we successfully measured peak splitting of the fundamental reflections from the intermediate phase using high energy synchrotron radiation. Careful analyses with the whole pattern decomposition method were carried out and clear evidence of an orthorhombic fundamental lattice with lattice constants a = 5.8285, b = 5.8142 and c = 5.7886 Å is presented.