Lattice fringe studies of (100) defects in enamel crystallites.
Lattice fringe studies of (100) defects in enamel crystallites.
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釉质微晶中 (100) 缺陷的晶格条纹研究。
DOI：
10.1111/j.1365-2818.1989.tb00583.x
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发表时间：
1989
影响因子：
2
通讯作者：
Lee,DD
中科院分区：
文献类型：
--
作者：
Lee,DD
鲨鱼（Nataprion brevirostrais）釉质微晶结构中的晶格缺陷已通过高分辨率透射电子显微镜中的晶格成像进行了研究。显示不同长度的线缺陷（100-2500埃）和宽度（10-30埃），并且沿着代表（100）晶格面的条纹观察到与主晶体不同的相行为。观察到退火过程，其中相位对比度的差异最终消失，并且缺陷本身成为缺陷的复杂部分。（100）型晶格平面。一系列的缺陷显示出相位对比的反转。通过检查在一定的焦点条件下的对比度行为，并通过采用菲涅耳衍射模式，缺陷区域的折射率被确定为低于磷灰石晶体的折射率。目前的研究结果表明，层间结构沿着（100）面是负责线缺陷观察釉磷灰石。
Lattice imperfections in the structure of shark (Nataprion brevirostrais) enamel crystallites have been studied by means of lattice‐imaging in a high‐resolution transmission electron microscope. Line defects exhibiting various lengths (100–2500 Å) and widths (10–30 Å) and demonstrating phase behaviour different from that of the host crystal were observed along the fringes representing (100) lattice planes.When defect sites were subjected to an electron beam, an annealing process was observed in which the difference in phase contrast eventually disappeared and the defect itself became an intricate part of the (100)‐type lattice planes.A through‐focal series of the defects show a reversal in phase contrast. By examining the contrast behaviour under certain focal conditions and by adopting the Fresnel diffraction mode, the refractive index of the defect regions was determined to be lower than that of the apatite crystal. Present findings suggest that the interlayering structure along the (100) planes is responsible for the line defects observed in enamel apatites.