Composite structure of BaTiO3 nanoparticle investigated by SR X-ray diffraction
Composite structure of BaTiO3 nanoparticle investigated by SR X-ray diffraction
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DOI：
10.1143/jpsj.71.1218
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发表时间：
2002-05-01
影响因子：
1.7
通讯作者：
Atake, T
中科院分区：
文献类型：
--
作者：
Aoyagi, S;Kuroiwa, Y;Atake, T
利用同步辐射（SR）高能X射线粉末衍射研究了尺寸为700、400、300和100 nm的BaTiO_3微粒的晶体结构和相变的尺寸效应。Rietveld精修结果表明，在300 K时，BaTiO 3微粒由四方相和立方相组成。研究了立方相BaTiO_3壳层包覆四方相BaTiO_3核层的结构模型。立方壳的厚度估计约为8 nm，无论颗粒尺寸如何，该厚度几乎恒定，并且立方组分的体积比随着颗粒尺寸的减小而增加。连续的相变检测，甚至在100 nm大小的颗粒，其中只有四氢呋喃组分经历的相变。
The size effects on the crystal structure and phase transitions have been investigated for BaTiO3 fine particles of 700, 400, 300 and 100 nm size, by means of powder diffraction using synchrotron radiation (SR) high-energy X-rays. The Rietveld refinement reveals that the BaTiO3 fine particles consist of tetragonal and cubic structure components at 300 K. The structure model indicating that the Cubic BaTiO3 shell covers the tetragonal BaTiO3 core is examined. The thickness of the cubic shell is estimated at approximately 8 nm, which is almost constant irrespective of particle sizes, and the Volume ratio of the cubic component increases with decreasing the particle size. Successive phase transitions are detected even in 100 nm size particles, where only the tetragonal component undergoes the phase transition.