Effect of Zn doping on the antiferromagnetism in kagome Cu4−xZnx(OH)6FBr

作     者：Zili Feng Yuan Wei Ran Liu Dayu Yan Yan-Cheng Wang Jianlin Luo Anatoliy Senyshyn Clarina dela Cruz Wei Yi Jia-Wei Mei Zi Yang Meng Youguo Shi Shiliang Li 

作者机构：Beijing National Laboratory for Condensed Matter Physics Institute of Physics Chinese Academy of Sciences Beijing 100190 China School of Physical Sciences University of Chinese Academy of Sciences Beijing 100190 China School of Physical Science and Technology China University of Mining and Technology Xuzhou 221116 China Collaborative Innovation Center of Quantum Matter Beijing 100190 China Heinz Maier-Leibnitz Zentrum (MLZ) Technische Universität München Garching D-85747 Germany Neutron Scattering Division Neutron Sciences Directorate Oak Ridge National Laboratory Oak Ridge Tennessee 37831 USA Semiconductor Device Materials Group National Institute for Materials Science 1-1 Namiki Tsukuba Ibaraki 305-0044 Japan Institute for Quantum Science and Engineering and Department of Physics Southern University of Science and Technology Shenzhen 518055 China CAS Center of Excellence in Topological Quantum Computation University of Chinese Academy of Sciences Beijing 100190 China 

出 版 物：《Physical Review B》 (Phys. Rev. B)

年 卷 期：2018年第98卷第15期

页      面：155127-155127页

核心收录：

基　　金：National Key R&D Program of China, (2016YFA0300502, 2016YFA0300604, 2017YFA0302900) National Thousand-Young Talents Program of China Office of Basic Energy Sciences Scientific User Facilities Division U.S. Department of Energy, USDOE National Natural Science Foundation of China, NSFC, (11374346, 11421092, 11474330, 11574359, 11674370, 11674406, 11774399, 11874401) National Natural Science Foundation of China, NSFC Chinese Academy of Sciences, CAS, (XDB07020000, XDB28000000) Chinese Academy of Sciences, CAS China Academy of Engineering Physics, CAEP, (2015AB03) China Academy of Engineering Physics, CAEP 

主　　题：Antiferromagnetism Quantum spin liquid Kagome lattice DC susceptibility measurements Neutron diffraction Specific heat measurements 

摘      要：Barlowite Cu4(OH)6FBr shows three-dimensional (3D) long-range antiferromagnetism, which is fully suppressed in Cu3Zn(OH)6FBr with a kagome quantum spin liquid ground state. Here we report systematic studies on the evolution of magnetism in the Cu4−xZnx(OH)6FBr system as a function of x to bridge the two limits of Cu4(OH)6FBr(x=0) and Cu3Zn(OH)6FBr(x=1). Neutron-diffraction measurements reveal a hexagonal-to-orthorhombic structural change with decreasing temperature in the x=0 sample. While confirming the 3D antiferromagnetic nature of low-temperature magnetism, the magnetic moments on some Cu2+ sites on the kagome planes are found to be vanishingly small, suggesting strong frustration already exists in barlowite. Substitution of interlayer Cu2+ with Zn2+ with gradually increasing x completely suppresses the bulk magnetic order at around x=0.4 but leaves a local secondary magnetic order up to x∼0.8 with a slight decrease in its transition temperature. The high-temperature magnetic susceptibility and specific-heat measurements further suggest that the intrinsic magnetic properties of kagome spin liquid planes may already appear from x0.3 samples. Our results reveal that the Cu4−xZnx(OH)6FBr may be the long-thought experimental playground for the systematic investigations of the quantum phase transition from a long-range antiferromagnet to a topologically ordered quantum spin liquid.