Site occupancy and magnetic moment of Fe in Ni2Mn0.3Fe0.7Ga alloy by neutron powder diffraction Study
Site occupancy and magnetic moment of Fe in Ni2Mn0.3Fe0.7Ga alloy by neutron powder diffraction Study
复制标题
Ni2Mn0.3Fe0.7Ga合金中Fe的位点占据和磁矩的中子粉末衍射研究
DOI：
10.1016/j.jallcom.2013.06.124
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发表时间：
2014
影响因子：
6.2
通讯作者：
T. Kanomata
中科院分区：
文献类型：
--
作者：
R. Y. Umetsu;D. Kikuchi;K. Koyama;K.Watanabe;Y.Yamaguchi;R. Kainuma;T. Kanomata
在14 ~ 500 K宽温度范围内对Ni2Mn0.3Fe0.7Ga合金进行了中子粉末衍射测量，该合金在冷却过程中在160 K左右发生了由L21型奥氏体向四层正交马氏体的马氏体相变。对于在500 K下在顺磁奥氏体相中测量的衍射图案，澄清了Mn和Fe原子在L21型结构中随机占据4asite。确定了200 K时铁磁性奥氏体相中Ni、Mn和Fe的磁矩分别为0.3、3.3和3.0 μB。Fe的磁矩明显大于2.2 μB的纯bcc-Fe。在14 K时，马氏体相中两个位置Fe的磁矩分别为2.3和2.6 μB，表明Fe在马氏体相中仍保持较大的磁矩。中子粉末衍射分析表明，马氏体相在14 K时的总磁矩为3.7 μB/f.u.，与3.5 μB/f. u的磁测量结果相一致。在4.2 K时。
Neutron powder diffraction measurements were carried out in a wide temperature range from 14 to 500 K for Ni2Mn0.3Fe0.7Ga alloy, which undergoes a martensitic transformation fromL21-type austenite phase to four layered orthorhombic-type martensite phase at about 160 K during cooling. For the diffraction pattern measured at 500 K in the paramagnetic austenite phase, it was clarified that the Mn and Fe atoms randomly occupied 4asite in theL21-type structure. Magnetic moments of Ni, Mn and Fe in the ferromagnetic austenite phase at 200 K were decided to be 0.3 and 3.3 and 3.0 μB, respectively. The magnetic moment of Fe is significantly larger than that in pure bcc-Fe of 2.2 μB. Magnetic moments of Fe in two sites at 14 K in the martensite phase were obtained to be 2.3 and 2.6 μB, respectively, suggesting that the comparatively large magnetic moments of Fe were kept even in the martensite phase. Total magnetic moment of the martensite phase at 14 K from the neutron powder diffractive analyses is 3.7 μB/f.u., being in good agreement with the result of the magnetic measurement of 3.5 μB/f.u. at 4.2 K.