X-RAY STUDY OF PHASE TRANSITIONS IN FERROELECTRIC PBNB2O6 AND RELATED MATERIALS
X-RAY STUDY OF PHASE TRANSITIONS IN FERROELECTRIC PBNB2O6 AND RELATED MATERIALS
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DOI：
10.1111/j.1151-2916.1960.tb13694.x
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发表时间：
1960-01-01
影响因子：
3.9
通讯作者：
SUBBARAO, EC
中科院分区：
文献类型：
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作者：
SUBBARAO, EC
研究了PbNb_2 O_6和Pb_（1 +x）（B_xNb_（1-x））O_6（其中B = Ti ~（4+），Zr ~（4+）或Sn ~（4+））在25° ~ 650°C之间的相变。用X光和荧光测量技术改性后的PbNb 2 O 6复合材料具有正交PbNb 2 O 6-型结构，额外的Pb 2+离子占据晶格空位。晶格参数a和c在加热过程中膨胀和收缩，直到在铁电居里温度，a和b突然重合，c略有膨胀。除了在居里温度下的相变，非化学计量化合物在450° C至300°C范围内显示出额外的相变。取决于成分。Pb 1 +x（Ti 2Nb 1-z）2 O 6中间相具有正交对称性。
The phase transitions in PbNb2O6and in compositions of the type Pb1+x(BxNb1‐x)O6, where B = Ti4+, Zr4+, or Sn4+, have been investigated between 25° and 650°C. using X‐ray and dilatometric techniques. The modified PbNb2o6compositions possess orthorhombic PbNb2O6‐type structure, with the additional Pb2+ions occupying vacant lattice sites. The lattice parametersaandcexpand andbcontracts during heating until, at the ferroelectric Curie temperature,aandbsuddenly coincide andcexpands slightly. Besides this phase change at the Curie temperature, the nonstoichiometric compounds show an additional phase transition in the range 450° to 300°C. depending on composition. The intermediate phase of Pbl+x(Ti2Nb1‐z)2O6appears to possess orthorhombic symmetry.