With Zn substitution to the three-dimensional antiferromagnetically ordered barlowite Cu_(4)(OH)_(6)FBr,Cu_(3)Zn(OH)_(6)FBr shows no magnetic phase transition down to 50 mK,and the system is suggested to be a two-dime...With Zn substitution to the three-dimensional antiferromagnetically ordered barlowite Cu_(4)(OH)_(6)FBr,Cu_(3)Zn(OH)_(6)FBr shows no magnetic phase transition down to 50 mK,and the system is suggested to be a two-dimensional kagomé quantum spin liquid[Chin.Phys.Lett.34077502(2017)].A key issue to identify such phase diagram is the exact chemical formula of the substituted compound.With Cu L-edge x-ray absorption spectrum(XAS)combined with the MultiX XAS calculations,we evaluate the Cu concentration in a nominal Cu_(3)Zn(OH)_(6)FBr sample.Our results show that although the Cu concentration is 2.80,close to the expected value,there is 34%residual Cu occupation in intersite layers between kagomé layers.Thus the Zn substitution of the intersite layers is not complete,and likely it intrudes the kagomé layers.展开更多
基金Project supported by the National Natural Science Foundation of China(Grant Nos.11934017 and 11774399)the Key Research and Development Program of China(Grant No.2016YFA0401000)+1 种基金the Chinese Academy of Sciences(Grant No.112111KYSB20170059)the K.C.Wong Education Foundation(Grant No.GJTD-2018-01)。
文摘With Zn substitution to the three-dimensional antiferromagnetically ordered barlowite Cu_(4)(OH)_(6)FBr,Cu_(3)Zn(OH)_(6)FBr shows no magnetic phase transition down to 50 mK,and the system is suggested to be a two-dimensional kagomé quantum spin liquid[Chin.Phys.Lett.34077502(2017)].A key issue to identify such phase diagram is the exact chemical formula of the substituted compound.With Cu L-edge x-ray absorption spectrum(XAS)combined with the MultiX XAS calculations,we evaluate the Cu concentration in a nominal Cu_(3)Zn(OH)_(6)FBr sample.Our results show that although the Cu concentration is 2.80,close to the expected value,there is 34%residual Cu occupation in intersite layers between kagomé layers.Thus the Zn substitution of the intersite layers is not complete,and likely it intrudes the kagomé layers.
