Microtexture of c-Axis-Oriented Polycrystalline Lanthanum Silicate Oxyapatite Formed by Reactive Diffusion
Microtexture of c-Axis-Oriented Polycrystalline Lanthanum Silicate Oxyapatite Formed by Reactive Diffusion
复制标题
反应扩散形成的c轴取向多晶硅酸镧氧磷灰石的显微织构
DOI：
10.1111/jace.14283
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发表时间：
2016
期刊：
影响因子：
--
通讯作者：
and T. Asaka
中科院分区：
文献类型：
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作者：
K. Fukuda;M. Okabe;and T. Asaka
在1873 K下对La 2SiO 5/La 2Si 2 O 7扩散偶退火25 h，在界面接触边界制备了晶粒取向的硅酸镧氧磷灰石（LSO）多晶。使用光学显微镜、透射电子显微镜、扫描电子显微镜和X射线衍射法（XRD）表征多晶LSO。从多晶体截面上的背散射电子图像中提取了单个晶粒的外形线信息。我们收集的电子背散射衍射图案和XRD图案，以确定，分别，单个晶粒的晶体取向和取向度的LSO多晶。反应区的形式是平行于原始接触边界的层，因此分类，根据晶粒尺寸分布和取向度的差异，分为三个不同的区域。在最内层的30 μm层厚区域，晶粒主要为圆形，尺寸小于16 μm。此外，该区域在三个区域中显示出最低的取向度。另一方面，该区域两侧的LSO颗粒尺寸要大得多，形态呈棱柱状; LSO晶体沿c轴沿着拉长，并由{001}、{304}和{100}面组成。单个晶粒几乎沿着它们的c-轴排列，其中它们的a-轴方向围绕公共c-轴随机分布。这三个区域的微观织构差异是由LSO晶体不同的生长行为引起的。
We annealed the La2SiO5/La2Si2O7diffusion couple at 1873 K for 25 h to prepare the grain‐oriented lanthanum silicate oxyapatite (LSO) polycrystal at the interfacial contact boundary. The polycrystalline LSO was characterized using optical microscopy, transmission electron microscopy, scanning electron microscopy, and X‐ray diffractometry (XRD). The external shape line information on individual crystal grains were extracted from the backscattered electron image on the section surface of the polycrystal. We collected the electron backscatter diffraction patterns and XRD patterns to determine, respectively, the crystallographic orientations of individual grains and orientation degrees of the LSO polycrystal. The reaction area was in the form of a layer parallel to the original contact boundary, and consequently categorized, based on the differences in grain size distribution and orientation degree, into three distinct regions. The innermost region with the layer thickness of 30 μm was composed mainly of the rounded and relatively small crystal grains with the size less than ~16 μm in diameter. Furthermore, this region showed the lowest orientation degree among the three regions. On the other hand, the LSO grains on both sides of this region were much larger in size and prismatic in morphology; the LSO crystals were elongated along thec‐axis, and built up of faces {001}, {304}, and {100}. The individual crystal grains were aligned almost along theirc‐axes, with theira‐axis directions being randomly distributed around the commonc‐axis. The differences in microtexture among the three regions would be induced by the distinct growth behaviors of LSO crystals.