arXivDaily arXiv每日学术速递 周一至周五更新
arXiv 0803.2787cond-mat.str-el
收藏

准一维反铁磁体Cu $_3$ Mo $_2$ O $_9$的反铁磁和弱铁磁长程序

Successive phase transitions to antiferromagnetic and weak-ferromagnetic long-range orders in quasi-one-dimensional antiferromagnet Cu$_3$Mo$_2$O$_9$

Tomoaki Hamasaki, Tomoyuki Ide, Haruhiko Kuroe, Tomoyuki Sekine, Masashi Hase, Ichiro Tsukada, Toshiro Sakakibara

摘要:

研究了具有反铁磁线性链和反铁磁线性链二聚体相互作用的Cu $_3$ Mo $_2$ O $_9$单晶的磁性,发现在$T_{\rm N} = 7.9$ K附近存在反铁磁二级相变.虽然弱的铁磁性的行为出现在较低的温度下,在低磁场,完整的reversible磁化不能检测到低至0.5 K。然而,当沿a轴的微小磁场反转时,在$T_{\rm c} \simeq 2.5$ K的弱铁磁(WF)相变以下的磁化强度中观察到跳跃,这表明矫顽力非常弱。平行于链的磁矩分量在$T_{\rm N}$下方形成AF长程有序(LRO),而垂直分量在零磁场下在$T_{\rm c}$上方无序,并在$T_{\rm c}$下方形成WF-LRO。此外,WF-LRO还通过甚至在$T_{\rm c}$和$T_{\rm N}$之间施加磁场来实现。这些结果可以用对称交换相互作用之间的磁阻挫和对称与非对称Dzyaloshinskiii-Moriya交换相互作用之间的竞争来解释。

英文摘要:

Investigation of the magnetism of Cu$_3$Mo$_2$O$_9$ single crystal, which has antiferromagnetic (AF) linear chains interacting with AF dimers, reveals an AF second-order phase transition at $T_{\rm N} = 7.9$ K. Although weak ferromagnetic-like behavior appears at lower temperatures in low magnetic fields, complete remanent magnetization cannot be detected down to 0.5 K. However, a jump is observed in the magnetization below weak ferromagnetic (WF) phase transition at $T_{\rm c} \simeq 2.5$ K when a tiny magnetic field along the a axis is reversed, suggesting that the coercive force is very weak. A component of magnetic moment parallel to the chain forms AF long-range order (LRO) below $T_{\rm N}$, while a perpendicular component is disordered above $T_{\rm c}$ at zero magnetic field and forms WF-LRO below $T_{\rm c}$. Moreover, the WF-LRO is also realized with applying magnetic fields even between $T_{\rm c}$ and $T_{\rm N}$. These results are explainable by both magnetic frustration among symmetric exchange interactions and competition between symmetric and asymmetric Dzyaloshinskii-Moriya exchange interactions.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

↑