Crystal=Lattice+basis •Infinitenumberofpossiblecrystalsbutfinitenumberofpossiblecrystal types,sotheyarecombinedtogetheraslatticeandbasis 2 Slide# 8/20/2006Dr.F.Nkansah–PhysicalElectronics CubicLattices SimpleCubicBody-centredcubicFace-centeredcubic
晶体结构;带有基元的晶格(Crystal Structure;Lattice with a Basis) 回到物理,对于一个实际的晶体,我们可以用一个布拉维格子以及原胞中各种粒子的组分来描述它。当讨论到抽象的布拉维格子和实际的晶体的区别是,我们会用到术语“晶体结构(crystal Structure)”。一个晶体结构可以看作是一个全同的物理单元复制了许多份,...
The most common crystal structure with the SC lattice is the CsCl structure. In this structure the basis consists of two atoms (one molecule of CsCl) with Cs at(0,0,0)and Cl ata(1/2,1/2,1/2)(or vice versa), where a is the cubic lattice constant. This structure is shown in fol...
The oblique coordinate system and basis vectors. Using an oblique coordinate system makes it necessary to use the methods of tensor analysis. The basis vectors E1,E2,E3 are called the covariant basis vectors. The position of any atom in the crystal lattice can then be written as (2.1)r=l1...
lattice charactersunit celllatticesThe chapter starts with a brief revision of the basic definitions of lattices and their bases followed by a discussion of the symmetry rules for the selection of the conventional crystallographic bases and unit cells. In Section 3.1.2 crystal lattices are described ...
When the crystal lattice is under pressure p, the self-diffusion coefficient changes and is then given by [24]DSD(T,p)=DSD0exp(−QSD/kT)exp(−pVSD/kT) The activation volume VSD can be obtained experimentally by measuring the self-diffusion coefficient as a function of an externally app...
In the case of centred cells, however, direction indices may take fractional values too, because the first lattice node after the origin along a direction can have fractional coordinates in a centred basis. This evidence is very often overlooked and an undue simplification of direction indices to...
The energy of formation of RbAlH 4 , addition of (H ) to [AlH 3 ], and other conversions was calculated on the basis of the energy of formation of the gaseous aluminum hydride ion. A correspondence was detected between the nature of the changes in the crystal lattice energy and certain...
Crystals with a not too high lattice symmetry exhibit a χ(2) nonlinearity. They are mainly used for parametric nonlinear frequency conversion (e.g. in frequency doublers and optical parametric oscillators), also for electro-optic modulators. Others only have χ(3) nonlinearities. Here, one may...
1–29, Tables 1–4 and References. Further information and data on structural characterization, electronic structure and optical transition analysis, interlayer properties, lattice vibrational properties, SHG and SPDC are listed. Rights and permissions Springer Nature or its licensor (e.g. a society ...