Evolution of incommensurate spin order with magnetic field and temperature in the itinerant antiferromagnet GdSi
Evolution of incommensurate spin order with magnetic field and temperature in the itinerant antiferromagnet GdSi
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DOI：
10.1103/physrevb.88.134404
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发表时间：
2013-10-07
影响因子：
3.7
通讯作者：
Rosenbaum, T. F.
中科院分区：
文献类型：
--
作者：
Feng, Yejun;Silevitch, D. M.;Rosenbaum, T. F.
GDSI显示出自旋密度波(SDW)有序，这是由相当大的局域力矩和部分嵌套的巡回电子的费米海共同作用产生的。利用磁输运、磁化和非共振磁X射线衍射技术，我们确定了反铁磁序不再稳定的21T以下磁场下GDSI的H-T相图，以及沿三个主要晶轴的场方向。虽然表征SDW的无公度磁有序向量在磁场下是健壮的，但这种化合物的多重自旋结构是高度灵活的，并且通过倾斜或自旋翻转过程相对于外加磁场旋转。反铁磁自旋密度总是与外加磁场方向垂直排列。相图由两种类型的相界来描述：一种是与晶格结构相变相关的共线自旋结构与平面自旋结构的分离，另一种是定义了仅与温度弱相关的自旋跳跃相变。沿每个晶轴的相图的主要特征可以用局域矩和整体费米表面物理的组合来解释。
GdSi exhibits spin-density-wave (SDW) order arising from the cooperative interplay of sizeable local moments and a partially nested Fermi sea of itinerant electrons. Using magnetotransport, magnetization, and nonresonant magnetic x-ray diffraction techniques, we determine the H-T phase diagrams of GdSi for magnetic fields up to 21 T, where antiferromagnetic order is no longer stable, and field directions along each of the three major crystal axes. While the incommensurate magnetic ordering vector that characterizes the SDW is robust under magnetic field, the multiple spin structures of this compound are highly flexible and rotate relative to the applied field via either canting or spin-flop processes. The antiferromagnetic spin densities always arrange themselves transverse to the applied magnetic field direction. The phase diagrams are delineated by two types of phase boundaries: one separates a collinear from a planar spin structure associated with a lattice structural transition, and the other defines a spin flop transition that is only weakly temperature dependent. The major features of the phase diagrams along each of the crystal axes can be explained by the combination of local moment and global Fermi surface physics at play.