Synthesis, Structure, and Magnetic Properties of the Layered Copper(II) Oxide Na2Cu2TeO6
详细信息 查看全文
- 作者：Jianxiao Xu ; Abdeljalil Assoud ; Navid Soheilnia ; Shahab Derakhshan ; Heather L. Cuthbert ; John E. Greedan ; Mike H. Whangbo ; and Holger Kleinke
- 刊名：Inorganic Chemistry
- 出版年：2005
- 出版时间：July 11, 2005
- 年：2005
- 卷：44
- 期：14
- 页码：5042 - 5046
- 全文大小：191K
- 年卷期：v.44,no.14(July 11, 2005)
- ISSN：1520-510X
文摘
A new quaternary layered transition-metal oxide, Na2Cu2TeO6, has been synthesized under air using stoichiometric(with respect to the cationic elements) mixtures of Na2CO3, CuO, and TeO2. Na2Cu2TeO6 crystallizes in the monoclinicspace group C2/m with a = 5.7059(6) Å, b = 8.6751(9) Å, c = 5.9380(6) Å, 
= 113.740(2)
, V = 269.05(5) Å3,and Z = 2, as determined by single-crystal X-ray diffraction. The structure is composed of 
[Cu2TeO6] layers withthe Na atoms located in the octahedral voids between the layers. Na2Cu2TeO6 is a green nonmetallic compound,in agreement with the electronic structure calculation and electrical resistance measurement. The magneticsusceptibility shows Curie-Weiss behavior between 300 and 600 K with an effective moment of 1.85(2) 
B/CuIIand 
c = -87(6) K. A broad maximum at 160 K is interpreted as arising from short-range one-dimensionalantiferromagnetic correlations. With the aid of the technique of magnetic dimers, the short-range order was analyzedin terms of an alternating chain model, with the surprising result that the stronger intrachain coupling involves asuper-superexchange pathway with a Cu-Cu separation of >5 Å. The J2/J1 ratio within the alternating chain refinedto 0.10(1), and the spin gap is estimated to be 127 K.
= 113.740(2), V = 269.05(5) Å3,and Z = 2, as determined by single-crystal X-ray diffraction. The structure is composed of [Cu2TeO6] layers withthe Na atoms located in the octahedral voids between the layers. Na2Cu2TeO6 is a green nonmetallic compound,in agreement with the electronic structure calculation and electrical resistance measurement. The magneticsusceptibility shows Curie-Weiss behavior between 300 and 600 K with an effective moment of 1.85(2) B/CuIIand c = -87(6) K. A broad maximum at 160 K is interpreted as arising from short-range one-dimensionalantiferromagnetic correlations. With the aid of the technique of magnetic dimers, the short-range order was analyzedin terms of an alternating chain model, with the surprising result that the stronger intrachain coupling involves asuper-superexchange pathway with a Cu-Cu separation of >5 Å. The J2/J1 ratio within the alternating chain refinedto 0.10(1), and the spin gap is estimated to be 127 K.