Department of Chemistry, Princeton University , Princeton, New Jersey 08544, United States.
Inorg Chem. 2013 Dec 2;52(23):13605-11. doi: 10.1021/ic402131e. Epub 2013 Nov 15.
We present the structure and magnetic properties of Na3Ni2BiO6, which is an ordered variant of the α-NaFeO2 structure type. This layered compound has a 2:1 ordering of (Ni(2+)/Bi(5+))O6 octahedra within the a-b plane and sodium in octahedra between the layers. The structure is presented in the space group C2/m, determined through a combination of single crystal X-ray, powder neutron, and powder X-ray diffraction. Temperature dependent magnetic susceptibility measurements show Na3Ni2BiO6 to display long-range antiferromagnetic ordering below 11 K, despite the dominance of ferromagnetic interactions above TN as indicated by a positive Weiss constant. Heat capacity measurements and low-temperature neutron diffraction support the magnetic ordering and are consistent with a TN of 10.4 K. A magnetic phase can be refined with (010) antiferromagnetic ordering along the b-axis in the honeycomb layer and moments aligned parallel to c. The compounds Na3Mg2BiO6 and Na3Zn2BiO6, synthesized as nonmagnetic analogues of Na3Ni2BiO6, are briefly described.
我们介绍了 Na3Ni2BiO6 的结构和磁性，它是 α-NaFeO2 结构类型的有序变体。这种层状化合物在 a-b 平面内具有 (Ni(2+)/Bi(5+))O6 八面体的 2:1 有序排列，钠原子位于层间的八面体中。结构在空间群 C2/m 中呈现，通过单晶 X 射线、粉末中子和粉末 X 射线衍射的组合确定。温度相关的磁化率测量表明，尽管在 TN 以上存在铁磁相互作用，导致正 Weiss 常数，但 Na3Ni2BiO6 在低于 11 K 时表现出长程反铁磁有序。热容测量和低温中子衍射支持磁有序，与 TN 为 10.4 K 一致。可以用（010）反铁磁沿 b 轴在蜂窝层中进行磁有序细化，并且磁矩沿 c 轴平行排列。简要描述了作为 Na3Ni2BiO6 的非磁性类似物合成的 Na3Mg2BiO6 和 Na3Zn2BiO6 化合物。
