论文标题
NAFE（WO $ _4 $）$ _ 2 $和mnwo $ _4 $的结构性二聚化（WO $ _4 $）
Structural dimerization in the commensurate magnetic phases of NaFe(WO$_4$)$_2$ and MnWO$_4$
论文作者
论文摘要
通过结构相关的MNWO $ _4 $和NAFE（WO $ _4 $）$ _ 2 $，中性衍射研究了通过相应磁性引起的结构失真和磁弹性耦合。这两个系统均表现出沿磁链的螺旋形和相应的旋转下降订单的竞争。在后一个相称的阶段中，fe $^{3+} $的交替平行和反平行排列分别是mn $^{2+} $矩矩矩量导致较大的债券角度调制，从而导致磁性二聚体化。对于NAFE（WO $ _4 $）$ _ 2 $，该结构失真已确定为低场上上下倒下的安排最强，并且结构改进产生了$ \ pm 1.15（16）$度的债券角度调制。在MNWO $ _4 $的相称阶段中，上部结构反射向相当的结构二聚化表示，因此与驱动多表皮级别的磁弹性耦合不同。在MNWO $ _4 $的不一致和多效相中，明显的Anharmonic二阶反射和三阶反射是由微小的相应分数产生的，可以将多种表皮域dep。
The structural distortion and magnetoelastic coupling induced through commensurate magnetism has been investigated by neutron diffraction in structurally related MnWO$_4$ and NaFe(WO$_4$)$_2$. Both systems exhibit a competition of incommensurate spiral and commensurate spin up-up-down-down ordering along the magnetic chains. In the latter commensurate phases, the alternatingly parallel and antiparallel arrangement of Fe$^{3+}$ respectively Mn$^{2+}$ moments leads to sizeable bond-angle modulation and thus to magnetic dimerization. For NaFe(WO$_4$)$_2$ this structural distortion has been determined to be strongest for the low-field up-up-down-down arrangement, and the structural refinement yields a bond-angle modulation of $\pm 1.15(16)$ degrees. In the commensurate phase of MnWO$_4$, superstructure reflections signal a comparable structural dimerization and thus strong magneto-elastic coupling different to that driving the multiferroic order. Pronounced anharmonic second- and third-order reflections in the incommensurate and multiferroic phase of MnWO$_4$ result from tiny commensurate fractions that can depin multiferroic domains.
