He Mingquan, Wang Xiao, Wang Liran, Hardy Frédéric, Wolf Thomas, Adelmann Peter, Brückel Thomas, Su Yixi, Meingast Christoph
Chongqing Key Laboratory of Soft Condensed Matter Physics and Smart Materials, College of Physics, Chongqing University, Chongqing 401331, People's Republic of China. Institute for Solid State Physics, Karlsruhe Institute of Technology, 76021 Karlsruhe, Germany.
J Phys Condens Matter. 2018 Sep 26;30(38):385702. doi: 10.1088/1361-648X/aada1e. Epub 2018 Aug 14.
We present high-resolution thermal-expansion and specific-heat measurements of single crystalline α-RuCl. An extremely hysteretic structural transition expanding over 100 K is observed by thermal-expansion along both crystallographic axes, which we attribute to a change of stacking sequence of the RuCl layers. Three magnetic transitions are observed, which we link to the different stacking sequences. Using our data and thermodynamic relations, we derive the uniaxial and hydrostatic pressure derivatives of all three magnetic transitions. Our results demonstrate that magnetic order of the major transition at ∼7 K should be totally suppressed by very moderate pressures of 0.3 GPa. Finally, we discuss why our results differ from recent hydrostatic pressure measurements and suggest a possible route to reaching the spin-liquid state in α-RuCl.
我们展示了对单晶α-RuCl的高分辨率热膨胀和比热测量结果。通过沿两个晶轴的热膨胀观察到一个跨越100 K的极其滞后的结构转变，我们将其归因于RuCl层堆叠顺序的变化。观察到三个磁转变，我们将其与不同的堆叠顺序联系起来。利用我们的数据和热力学关系，我们推导出了所有三个磁转变的单轴和静水压力导数。我们的结果表明，在约7 K时主要转变的磁有序应该会被0.3 GPa的非常适度的压力完全抑制。最后，我们讨论了为什么我们的结果与最近的静水压力测量结果不同，并提出了在α-RuCl中达到自旋液体状态的可能途径。
