Michiue Y, Onoda M, Watanabe M, Brown F, Kimizuka N
Advanced Materials Laboratory, National Institute for Materials Science, 1-1 Namiki, Tsukuba, Ibaraki 305-0044, Japan.
Acta Crystallogr B. 2001 Aug;57(Pt 4):458-65. doi: 10.1107/s0108768101005432. Epub 2001 Jul 25.
The structure of pseudohexagonal-type InFe(1--x--4 delta)Ti(x+3 delta)O(3+x/2) (x = 0.61, delta = 0.04), indium iron titanium oxide, was refined on the basis of a four-dimensional superspace group. The crystal has a compositely modulated structure consisting of two orthorhombic subsystems mutually incommensurate in b. The first subsystem InFe(1-x-4 delta)Ti(x+3 delta)O(2) has a delafossite structure with lattice parameters a = 5.835 (3), b(1) = 3.349 (1) and c = 12.082 (7) A. The second subsystem with b(2) = 2.568 (6) A consists of O atoms. The superspace group of the overall structure is Ccmm(1, 1.305, 0)s00, which can be converted to Amam(0, 0, 0.305)0s0 (No. 63.8). Refinement on 1105 unique reflections converged to R = 0.0303 and wR = 0.0325 with 63 structural parameters. The structure of the first subsystem is the alternate stacking of an edge-shared InO(6) octahedral layer and an Fe/Ti triangle-lattice plane along c. A sheet of O atoms in the second subsystem is also extending on the Fe/Ti plane, where displacive modulation of atoms is prominent.
基于四维超空间群对六方伪型铟铁钛氧化物InFe(1–x–4δ)Ti(x + 3δ)O(3 + x/2)（x = 0.61，δ = 0.04）的结构进行了精修。该晶体具有复合调制结构，由两个在b方向相互不相称的正交子系统组成。第一个子系统InFe(1 - x - 4δ)Ti(x + 3δ)O₂具有铜铁矿结构，晶格参数a = 5.835(3)，b₁ = 3.349(1)，c = 12.082(7) Å。第二个子系统b₂ = 2.568(6) Å，由O原子组成。整体结构的超空间群为Ccmm(1, 1.305, 0)s00，可转换为Amam(0, 0, 0.305)0s0（编号63.8）。对1105个独立反射进行精修，收敛得到R = 0.0303，wR = 0.0325，有63个结构参数。第一个子系统的结构是一个边共享的InO₆八面体层和一个沿c方向的Fe/Ti三角形晶格平面交替堆叠。第二个子系统中的一层O原子也在Fe/Ti平面上延伸，原子的位移调制很显著。
