PHASE TRANSITIONS IN ANTIFERROELECTRIC PBHFO3
PHASE TRANSITIONS IN ANTIFERROELECTRIC PBHFO3
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DOI：
10.1103/physrev.91.812
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发表时间：
1953-01-01
期刊：
影响因子：
--
通讯作者：
PEPINSKY, R
中科院分区：
文献类型：
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作者：
SHIRANE, G;PEPINSKY, R
通过介电和结构测量研究了phbhfo3陶瓷的相变。在室温下介电常数约为90，在163℃时介电常数有一个小的异常，在215℃时介电常数达到540的峰值。然而，P−E关系几乎是线性的，在这个温度范围内没有铁电磁滞回。在室温下，phbhfo3具有钙钛矿型四方晶格，a= 4.136 a, c = 0.991，粉末x射线照片显示出一些与pbzro3基本相同的上层结构线。这表明phbhfo3在163℃以下是PbZr o3型的反铁电晶体，163 ~ 215℃之间的晶体结构也是基于四方晶格；但轴比c a更接近于1(0.997)，观测到的上部结构线与最低相不同。因此，中间相是另一种反铁电相，具有与最低相不同类型的偶极子排列。在215℃时，它变成准电性的，同时变为立方结构。
Phase transitions in ceramic PbHf O 3 have been studied by dielectric and structural measurements. The dielectric constant is about 90 at room temperature, and its temperature dependence shows a small anomaly at 163 C and a pronounced peak of 540 at 215 C. The P− E relation, however, is almost linear, showing no ferroelectric hysteresis loops within this temperature range. At room temperature PbHf O 3 has a tetragonal lattice of the perovskite type with a= 4.136 A and c a= 0.991, and a powder x-ray photograph shows some superstructure lines which have essentially the same character as those of PbZr O 3. This shows that PbHf O 3 is an antiferroelectric of the PbZr O 3 type below 163 C. The crystal structure between 163 C and 215 C is also based on a tetragonal lattice; but the axial ratio c a is much closer to unity (0.997), and the observed superstructure lines are different from those of the lowest phase. Thus the intermediate phase is another antiferroelectric phase, with a different type of dipole arrangement from that of the lowest phase. At 215 C, it becomes paraelectric, accompanied by a change to a cubic structure.