Structure change of Ca1–xSrxTiO3 perovskite with composition and pressure
Structure change of Ca1–xSrxTiO3 perovskite with composition and pressure
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DOI：
10.2138/am-2002-8-917
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发表时间：
2002-08
影响因子：
3.1
通讯作者：
T. Yamanaka;Noriyuki Hirai;Y. Komatsu
中科院分区：
文献类型：
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作者：
T. Yamanaka;Noriyuki Hirai;Y. Komatsu
摘要 在环境条件下使用单晶对 (Ca1-xSrx)TiO3 (x = 0.0、0.25、0.5、0.6、0.65 和 1.0) 固溶体进行结构精修。它们的晶格常数、c/a轴比和晶胞体积表明从斜方晶系到立方晶系通过四方相的连续变化。斜方结构在x=0.0和x=0.6之间是连续的，并且x=0.65处的相显示出具有空间群I4/mcm的四方结构。随着Sr取代度的增加，对称性变为具有Pm3̄m空间群的立方体。 ABO3 钙钛矿中的 A-O 和 B-O 距离被确定为 A 阳离子（Ca 和 Sr）组成的函数。还评估了 TiO6 八面体与 (Ca1-xSrx)TiO3 的 x 连接的倾斜角和旋转角。使用金刚石砧池在 3.5、4.1 和 7.0 GPa、300 K 下对 Ca0.35Sr0.65TiO3 钙钛矿进行单晶结构细化。在 3.5 GPa 下，四方相转变为空间群 Pbnm 的斜方结构。讨论了 VIIIA2+VIB4+O3 钙钛矿在压缩下的多晶型转变。
Abstract Structure refinements of solid solutions of (Ca1-xSrx)TiO3 (x = 0.0, 0.25, 0.5, 0.6, 0.65, and 1.0) were undertaken using single crystals at ambient conditions. Their lattice constants, c/a axial ratios, and cell volumes indicate continuous changes from orthorhombic to cubic through a tetragonal phase. The orthorhombic structure is continuous between x = 0.0 and x = 0.6, and a phase at x = 0.65 shows a tetragonal structure with space group I4/mcm. With increasing Sr substitution, the symmetry changes to cubic with Pm3̄m space group. A-O and B-O distances in ABO3 perovskite were determined as a function of the composition of the A cation (Ca and Sr). Tilting and rotation angles of the TiO6 octahedral linkage with x of (Ca1-xSrx)TiO3 were also evaluated. Single-crystal structure refinements of Ca0.35Sr0.65TiO3 perovskite at 3.5, 4.1, and 7.0 GPa at 300 K were carried out using a diamond anvil cell. The tetragonal phase transforms to an orthorhombic structure with space group Pbnm at 3.5 GPa. The polymorphic transition of VIIIA2+VIB4+O3 perovskites under compression is discussed.