摘要
The geometrically frustrated iridate La_(3)Ir_(3)O_(11) with strong spin–orbit coupling and fractional valence was recently predicted to be a quantum spin liquid candidate at ambient conditions. Here, we systematically investigate the evolution of structural and electronic properties of La_(3)Ir_(3)O_(11) under high pressure. Electrical transport measurements reveal an abnormal insulating behavior rather than metallization above a critical pressure P_(c) ~ 38.7 GPa. Synchrotron x-ray diffraction(XRD)experiments indicate the stability of the pristine cubic KSbO_(3)-type structure up to 73.1 GPa. Nevertheless, when the pressure gradually increases across P_(c), the bulk modulus gets enhanced and the pressure dependence of bond length d_(Ir-Ir) undergoes a slope change. Consistent with the XRD data, detailed analyses of Raman spectra reveal an abnormal redshift of Raman mode and a change of Raman intensity around P_(c). Our results demonstrate that the pressure-induced insulating behavior in La_(3)Ir_(3)O_(11) can be assigned to the structural modification, such as the distortion of IrO_6 octahedra. These findings will shed light on the emergent abnormal insulating behavior in other 5 d iridates reported recently.
作者
Chun-Hua Chen
Yong-Hui Zhou
Ying Zhou
Yi-Fang Yuan
Chao An
Xu-Liang Chen
Zhao-Ming Tian
Zhao-Rong Yang
陈春华;周永惠;周颖;袁亦方;安超;陈绪亮;田召明;杨昭荣(Anhui Province Key Laboratory of Condensed Matter Physics at Extreme Conditions,High Magnetic Field Laboratory,Chinese Academy of Sciences,Hefei 230031,China;Science Island Branch of Graduate School,University of Science and Technology of China,Hefei 230026,China;Institutes of Physical Science and Information Technology,Anhui University,Hefei 230601,China;School of Physics,and Wuhan National High Magnetic Field Center,Huazhong University of Science and Technology,Wuhan 430074,China;High Magnetic Field Laboratory of Anhui Province,Hefei 230031,China)
基金
supported by the National Key Research and Development Program of China (Grant Nos. 2018YFA0305704 and 2016YFA0401804)
the National Natural Science Foundation of China (Grant Nos. U1632275, U1932152, 11874362, 11704387, 11804344, 11804341, 11974016, U19A2093, and U1832209)
the Natural Science Foundation of Anhui Province
China (Grant Nos. 1808085MA06, 2008085QA40, and 1908085QA18)
the Users with Excellence Project of Hefei Center CAS (Grant No. 2020HSC-UE015)
the Collaborative Innovation Program of Hefei Science Center CAS (Grant No. 2020HSC-CIP014)
A portion of this work was supported by the High Magnetic Field Laboratory of Anhui Province under Contract No. AHHM-FX-2020-02
Yonghui Zhou was supported by the Youth Innovation Promotion Association CAS (Grant No. 2020443)。
