STRUCTURE OF RHOMBOHEDRAL FERROELECTRIC BARIUM-TITANATE
STRUCTURE OF RHOMBOHEDRAL FERROELECTRIC BARIUM-TITANATE
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DOI：
10.1080/00150197408243970
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发表时间：
1974-01-01
期刊：
影响因子：
0.8
通讯作者：
HEWAT, AW
中科院分区：
文献类型：
--
作者：
HEWAT, AW
中子粉末衍射图谱分析技术已用于表明钛酸钡的最低温度相是菱面体 R3m，在 77.4 K 时晶胞角 α = 89.868 ± 0.004°。立方钙钛矿位置的原子位移沿 [111] 方向，大小为 δ (Ba) = 0.001 ± 21 Å, δ(Ti) = 0.091 Å 和 δ(OI) = δ (OII) = δ(OIII) = -0.091 ± 14 Å。氧八面体因垂直于该铁电轴的附加氧位移 δ⊥(O) = 0.023 ± 13 Å 而略有变形。这些值产生 34 ± 7 μC。 cm-1 为该相的自发极化，与测量值 33.5 μC.cm-1 非常吻合。
The Profile Analysis technique for neutron powder diffraction patterns has been used to show that the lowest temperature phase of barium titanate is rhombohedral R3m with cell angle α = 89.868 ± 0.004°at 77.4 K. The atomic displacements from the cubic perovskite positions are along [111], and have magnitudes of δ (Ba) = 0.001 ± 21 Å, δ(Ti) = 0.091 Å and δ(OI) = δ (OII) = δ(OIII) = -0.091 ± 14 Å. The oxygen octahedron is slightly distorted by an additional oxygen displacement of δ⊥(O) = 0.023 ± 13 Å perpendicular to this ferroelectric axis. These values yield 34 ± 7 μC. cm-1 for the spontaneous polarization in this phase, in good agreement with the measured value of 33.5 μC.cm-1.