论文标题
使用中子衍射技术的锶掺杂钡钛酸钡的合成和表征
Synthesis and Characterization of Strontium Doped Barium Titanates using Neutron Diffraction Technique
论文作者
论文摘要
在本研究中，通过X射线和中子粉末衍射技术研究了BATIO3中SR逐渐掺杂引起的结构变化。通过PVA蒸发方法合成BA1-XSRXTIO3（X = 0.0、0.5和1.0）样品，并通过X射线衍射实验证实了纯度。之后，使用计算机程序Rietan-2000和FullProf通过Rietveld最小二乘数据改进方法进行中子衍射实验，并通过Rietveld最小二乘数据改进方法分析衍射数据，以确定各种晶体学结构参数。还通过数据细化方法确定了阳离子和阴离子位置坐标，该方法证实了BA和SR原子具有四面体A位点和Ti原子在所有三个样品BATIO3，BA0.5SR0.5TIO3和SRTIO3的所有三个样品中都具有八面体B位点。此外，晶格参数值表明，BA1-XSRXTIO3结构在x = 0.5之前从四方到立方的相变。观察到的和计算出的曲线之间的并发是极好的，并且与先前报道的值一致。此外，对电荷密度测量进行了基于MEM的分析。
In the present study, structural changes due to gradual doping of Sr in BaTiO3 were investigated by both x-ray and neutron powder diffraction techniques. Ba1-xSrxTiO3 (x=0.0, 0.5 and 1.0) samples were synthesized by PVA evaporation method and purity was confirmed by x-ray diffraction experiment. After that, neutron diffraction experiments were carried out and diffraction data were analyzed by Rietveld least-square data refinement method using the computer program RIETAN-2000 and FullProf to determine various crystallographic structural parameters. The cation and anion position coordinates were also determined from the data refinement method which confirmed that Ba and Sr atoms possess tetrahedral A site and Ti atoms possess octahedral B site for all three samples BaTiO3, Ba0.5Sr0.5TiO3, and SrTiO3, respectively. Moreover, the lattice parameter values indicate, Ba1-xSrxTiO3 structure undergoes a phase transition from tetragonal to cubic somewhere before x=0.5. The concurrences between observed and calculated profiles were excellent and well consistent with the previously reported values. Furthermore, MEM based analysis was done for charge density measurement.
