title: Two S = 1/2 one-dimensional barium copper phosphates showing antiferromagnetic and ferromagnetic intrachain interactions.
abstract: Two barium copper phosphates, BaCu2(PO4)2(H2O) (1) and Ba2Cu(HPO4)(PO4)(OH) (2), were synthesized under mild hydrothermal conditions. The Cu cation in 1 adopts a CuO4(H2O) square pyramidal coordination configuration, forming alternating chains along the b axis through alternative corner and edge sharing, while the geometry of the Cu center in 2 is a CuO4(OH)2 octahedron which further connects each other by edge sharing to constitute uniform chains along the b axis. Magnetic behaviors of both compounds were analyzed by susceptibility, magnetization and heat capacity measurements. The dominant intrachain couplings are antiferromagnetic in 1 with a long-range ordering at 14 K and ferromagnetic in 2 without long-range ordering above 2 K. The first principles calculations indicate that the intrachain ferromagnetic couplings in 2 originate from Cu(1)-O(7)H-Cu(1) dpσ correlation superexchanges. The susceptibility data of compounds 1 and 2 are fitted by using suitable antiferromagnetic chain and ferromagnetic chain models, respectively. In addition, we report the results of the infrared and thermal measurements of both the compounds.
authors.affiliation: State Key Laboratory of Structural Chemistry, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou, 350002, P. R. China. xianghp@fjirsm.ac.cn hcz1988@hotmail.com hezz@fjirsm.ac.cn.
authors.forename: Ming
authors.initials: M
authors.lastname: Yang
authors.affiliation: State Key Laboratory of Structural Chemistry, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou, 350002, P. R. China. xianghp@fjirsm.ac.cn hcz1988@hotmail.com hezz@fjirsm.ac.cn and University of Chinese Academy of Sciences, Beijing, 100049, P. R. China.
authors.forename: Meiyan
authors.initials: M
authors.lastname: Cui
authors.affiliation: State Key Laboratory of Structural Chemistry, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou, 350002, P. R. China. xianghp@fjirsm.ac.cn hcz1988@hotmail.com hezz@fjirsm.ac.cn.
authors.forename: Suyun
authors.initials: S
authors.lastname: Zhang
authors.affiliation: State Key Laboratory of Structural Chemistry, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou, 350002, P. R. China. xianghp@fjirsm.ac.cn hcz1988@hotmail.com hezz@fjirsm.ac.cn.
authors.forename: Hongping
authors.initials: H
authors.lastname: Xiang
authors.affiliation: State Key Laboratory of Structural Chemistry, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou, 350002, P. R. China. xianghp@fjirsm.ac.cn hcz1988@hotmail.com hezz@fjirsm.ac.cn.
authors.forename: Wenbin
authors.initials: W
authors.lastname: Guo
authors.affiliation: State Key Laboratory of Structural Chemistry, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou, 350002, P. R. China. xianghp@fjirsm.ac.cn hcz1988@hotmail.com hezz@fjirsm.ac.cn.
authors.forename: Zhangzhen
authors.initials: Z
authors.lastname: He