New-type phase transition of Li2RuO3 with honeycomb structure
New-type phase transition of Li2RuO3 with honeycomb structure
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DOI：
10.1143/jpsj.76.033705
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发表时间：
2007-03-01
影响因子：
1.7
通讯作者：
Kakurai, Kazuhisa
中科院分区：
文献类型：
--
作者：
Miura, Yoko;Yasui, Yukio;Kakurai, Kazuhisa
在Li2RuO3中发现了一种新型的结构转变，它具有一种边缘共享的RuO6八面体的蜂窝晶格。随着温度T的降低，电阻率在T = T-c处出现了类似于540 K的异常增大，表明发生了类似（金属向绝缘体）的转变，磁化率也急剧下降。详细的结构分析表明，高温空间群C2/m在Tc时变为P2(1)/m。最引人注目的事实是，六边形中6对Ru-Ru对中的2对在低温相中键长显著减少，这表明由这些Ru-Ru对分子轨道的形成驱动了一种新型的相变。
A new-type structural transition has been found in Li2RuO3 with a honeycomb lattice of edge-sharing RuO6 octahedra. With decreasing temperature T, the electrical resistivity exhibits an anomalous increase at T = T-c similar to 540 K, suggesting the (metal -to-insulator)-like transition, and the magnetic susceptibility also shows a sharp decrease. Detailed structure analyses have revealed that the high-temperature space group C2/m changes to P2(1)/m at Tc. The most striking fact is that a significant reduction of the bond lengths is found between two of the six Ru-Ru pairs of the hexagon in the low-temperature phase, indicating a new-type phase transition driven by the formation of the molecular orbits of these Ru-Ru pairs.