Dynamics of the magnetic and structural α-ε phase transition in iron -: art. no. 255503
Dynamics of the magnetic and structural α-ε phase transition in iron -: art. no. 255503
复制标题
DOI：
10.1103/physrevlett.93.255503
复制
发表时间：
2004-12-17
影响因子：
8.6
通讯作者：
Pascarelli, S
中科院分区：
文献类型：
--
作者：
Mathon, O;Baudelet, F;Pascarelli, S
我们用x射线磁圆二色性和x射线能量色散谱同时研究了高压铁bcc到hcp的相变。这两种技术的结合使我们能够同时获得铁在压力下的结构和磁性状态的信息。同时观察到的磁性和结构转变是尖锐的。两者都是与理论预测一致的一阶。观察到的转变压力范围（2.4+/-0.2 GPa）比文献中通常引用的范围（8 GPa）窄。我们的数据表明，磁性转变稍早于结构的，这表明铁的体心立方相的不稳定性的起源与压力的增加是由于压力对磁性的影响，如自旋极化的全势能总能量计算预测。
We have studied the high-pressure iron bcc to hcp phase transition by simultaneous x-ray magnetic circular dichroism and x-ray absorption spectroscopy with an x-ray energy dispersive spectrometer. The combination of the two techniques allows us to obtain simultaneously information on both the structure and the magnetic state of iron under pressure. The magnetic and structural transitions simultaneously observed are sharp. Both are of first order in agreement with the theoretical prediction. The pressure domain of the transition observed (2.4+/-0.2 GPa) is narrower than that usually cited in the literature (8 GPa). Our data indicate that the magnetic transition slightly precedes the structural one, suggesting that the origin of the instability of the bcc phase in iron with increasing pressure is to be attributed to the effect of pressure on magnetism as predicted by spin-polarized full-potential total energy calculations.