In this paper , we study the relationship between the lattice constant and the grain size of the nanocrystallites from both the theory and the experiment in order to find out a united principle to explain these phenomena 本文从实验和理论两个方面研究纳米晶的晶粒线度与晶格常数之间的关系,以致力于找出这类问题的一个统一的规律。
Due to the change in lattice constant and the distortion of energy band , strained si exhibits great mobility enhancement compared with the conventional si material , and it is the critical reason for the wide application of strained si mosfets 由于晶格常数的改变,应变硅中载流子的迁移率高于普通硅材料,这是应变硅mosfet性能提高的根本原因。
The pure sample with spinel structure can be easily prepared by optimizing the processing parameters . the typical product is limnio4 with the cell constant a = 8 . 235 and the powder size belongs to nanometer and sub - micrometer 表明用改进的柠檬酸配合法可以合成出单相正尖晶石limn _ 2o _ 4 ,其典型的试样组成为limn _ 2o _ 4 ,晶格常数= 8 . 235 ,粒度大小为纳米级。
The similarities in crystal structures and lattice constants between the lanio3 and bst films offer the benefits of better lattice matching and structural compatibilities , and the potential for improved dielectric and leakage current properties 研究表明lanio _ 3和bst薄膜在晶格结构和晶格常数上的相似性给bst薄膜和底电极提供了更好的晶格匹配,从而改善bst薄膜的性质。
The theoretical results are in good agreement with the experimental ones qualitatively . however , as to y - fe _ ( 2 ) o _ ( 3 ) nanocrystallites , the lattice constant increases with the decreasing of the grain size . it is opposite to the result of ionic crystallites 然而,丫一f勺伪纳米微粒的晶格常数随着晶粒线度的减小而增大,与我们实验和理论中对离子晶体所讨论的结果恰好相反。
During the calculation of crystallography , we always need to make some calculation such as vector length , angle between vectors or planes etc . this is a group of scilab functions which can make some common calculation 晶体学计算过程中经常需要计算矢量长度、矢量夹角等。此scilab工具箱提供了一组适用于任何晶体结构的函数,可以在输入晶格常数的前提下,计算一些常用的晶体学数据。
The investigation of structure by x - ray diffraction shows that crystal parameters changes clearly when percenting ca and la into pbtio _ 3 , it was caused by the ca ion and la ion replaced the pb ion of a position in perovskite compound , that bring lattice mismatch and asymmetrical replace 在pbtio _ 3中掺入la和ca可以有效改变薄膜的晶格常数,这是因为在abo _ 3型化合物中,钙离子、镧离子取代了a位的铅离子,造成晶格失配和不对称取代。
In contrast , the lcmo thin films grown on lao substrates show an in - plane compressive stress . the afm images suggest that at the annealing temperature range between 650 and 750 , with the annealing temperature increase , the grain sizes increase , the rms increase 沉积在sto基片上的lcmo薄膜在面内方向受张应力作用,垂直方向上的晶格常数相对缩小,沉积于lao基片上的lcmo薄膜在面内方向受压应力作用,垂直方向上的晶格常数相对增大。
Srtio _ 3 ( sto ) thin films exhibit a large electric field dependence of dielectric permittivity . the microwave surface resistance of yba2cu3o7 - x ( ybco ) is much lower than that of the normal conductor . the typical value of rs for ybco epitaxial thin film is smaller than 1 m 在低温下, srtio _ 3 (简写为sto )薄膜具有强烈的非线性介电性质,即:介电常数随外加直流电场变化而变化; yba2cu3o7 - x (简写为ybco )具有极低的微波表面电阻, rs ( 10ghz , 77k ) < 1m ,而且它们的晶体结构相似,晶格常数匹配以及化学性质相容。
The phase structure , the lattice constant , crystal grain diameter of the samples was obtained by the x - ray diffractions ( xrd ) spectra . their relations are showed respectively . influence of grain size on the lattice constant of several kind of phase structure was studied theoretically by interaction energy between atoms in nanocrystallites 其次,从结合能的角度出发,研究了nacl结构和cscl结构的离子晶体,面心立方( fcc ) 、体心立方( bcc )金属晶体以及简立方( scc ) 、面心立方( fcc ) 、体心立方( bcc )结构分子晶体的晶粒线度对晶格常数的影响。