Density function theory is suitable for the multi - electron system by considering a single - electron system . the parameters such as binding energy 、 lattice constants 、 bulk modules calculated by density function theory of semiconductor and metal materials have shown to be in good agreement with the experimental results . as such , the first principles study of the condensed matter materials based on density function theory is being paid more and more attention 运用局域密度泛函理论可将多电子系统转化为单电子系统,由此对各类半导体材料和金属材料的结合能、晶格常数、体变模量做计算得到了与实验符合很好的结果,使之成为近年来电子理论中的一项重要的成就。
However the study of metal - oxide hetero - interface is relatively less because the properties of metals and oxides usually differ extremely from each other . contrary to metals , the oxides are usually very brittle , elastically stiffer , insulating and exhibit less thermal expansion and their crystal lattice constants are different from metals . moreover , the preparation of specimen of metal - oxide interface is very difficult , the observation of searching a suitable interface under the electron microscope is also a tedious work 然而，对金属-氧化物界面结构的研究却相对少一些，这主要是由于金属与氧化物之间的性质相差非常大，与金属相反，氧化物通常很脆、绝热、热膨胀系数小，晶格常数也不同于金属，有的甚至相差很大，而且，制备金属-氧化物界面比较困难，在电子显微镜下全面地观察一个合适的界面也是一项令人乏味的工作。
By home analyzing the experiment result , we think that the covalent bond is more than the electrovalent bond in y - fe _ ( 2 ) o _ ( 3 ) crystallites . it is the dominating reason that the dependence of y - fe _ ( 2 ) o _ ( 3 ) crystallites grin size on lattice constant is differ from one of the ionic crystallites 通过对实验结果的进一步分析，我们认为其主要原因是在丫一fezo3中原子之间结合的共价性超过了离子性，因而导致了它们的晶格常数随晶粒线度的变化趋势和离子晶体正好相反。
However , it is not easy to incorporate large n concentration in gap due to the large differences in lattice structure ( gan belongs to wurtzite structure while gap zinc blende structure ) and in lattice constant ( ~ 20 % ) between gan and gap , which will lead to an extremely large miscibility gap 然而要在gap中实现高浓度的掺氮并不容易。这主要是由于gap和gan之间较大的物理特性的差异，特别是晶格结构和晶格常数的差异，使得gap和gan存在较大的可混溶性间隙，从而难以生长高质量的高掺氮的gap材料。
Pure cdte films have high electrical resistivity and are slightly p - type , due to the formation of cd vacancies in the cdte lattice acting as acceptor centers . the sheet resistivity of films are about 1010 ? / ? . the sheet hole concentration is 105 - 6 / cm2 and the hall mobility is about hundreds cm2 / v . s . the structural and electrical properties of cdte films doped te are markedly different from pure cdte films ，面载流子浓度约105 - 6 / cm2 ，载流子迁移率为几百cm2 / v . s ；掺杂te元素后，薄膜衍射峰强增大，薄膜结构上出现了第二种相成分?六方结构的te ，由衍射峰强判断该相比例较小，同时cdte薄膜的衍射峰向低角度偏移，晶格< wp = 5 >常数增大。
Compound powders of tib2 and mgo were prepared by ball milling with tio2 , b2o3 and mgo as raw powders . the changes of temperature and heat effect of reaction during ball milling were studied , and reactive thermodynamics was analyzed . components , granularity and microstructure of the resultants were examined , and the crystal lattice constants of the resultants was computed and analyzed 研究了tib _ 2制备过程中的温度变化和热效应，并对反应的热力学进行了分析；检测了生成产物的成分、粉末粒度和组织形貌；对球磨后产物的晶格常数等进行了分析计算；对反应原料tio _ 2粉、 b _ 2o _ 3粉和mg粉组成的三元系进行了dta分析；研究了tib _ 2球磨制备过程中的动力学影响因素；对球磨反应的机理进行了探讨。
As the heat treatment temperature increasing , the lattice constant in la0 . 55ca0 . 45mn0 . 27ti0 . 73o3 and la0 . 56ca0 . 44mn0 . 38tio . 62o3 thin film deposited on si ( 100 ) increases due to the existence of strain between thin film and silicon substrate , and the the lattice constant in la0 . 69ca0 . 31mno . 37ti0 . 63o3 thin film deposited on ag / si ( 100 ) decreases due to the stress between thin film and silicon substrate 石20 :薄膜受张应力，随热处理温度升高晶格常数增大。 ag / si ( 100 )基板上的lao . 69c盯3lmn0 . 37ti06303薄膜受压应力，随热处理温度升高晶格常数减小。
