1-1.lattice parameter The lattice constant, or lattice parameter, refers to the constant distance between unit cells in a crystal lattice. Lattices in three dimensions generally have three lattice constants, referred to as a, b, and c. However, in the special case of cubic crystal structures, all of the constants are [...]
1-2.Stacking Sequence If we are going to make a laminated structure, we must know the thickness of each ply and the angle of each ply traditionally in degrees defined from the top layer down.
1-3.Mohs Hardness Rough measure of the resistance of a smooth surface to scratching or abrasion, expressed in terms of a scale devised(1812)by the German mineralogist Friedrich Mohs. The Mohs hardness of a mineral is determined by observing whether its surface is scratched by a substance of known or defined hardness.
1-4.Density The mass density or density of a material is its mass per unit volume. The symbol most often used for density is ρ (the lower case Greek letter rho). Mathematically, density is defined as mass divided by volume:
1-5.Thermal Expansion Coefficient Thermal expansion is the tendency of matter to change in volume in response to a change in temperature. When a substance is heated, its particles begin moving more and thus usually maintain a greater average separation. Materials which contract with increasing temperature are rare; this effect is limited [...]
In optics the refractive index (or index of refraction) n of a substance (optical medium) is a number that describes how light, or any other radiation, propagates through that medium. Refractive index is the basic property of optical crystals, and it is an important parameter to study the properties of [...]
In solid state physics, a band gap, also called an energy gap or bandgap, is an energy range in a solid where no electron states can exist. In graphs of the electronic band structure of solids, the band gap generally refers to the energy difference (in electron volts) between [...]
1-8.Electrical Breakdown The term electrical breakdown or electric breakdown has several similar but distinctly different meanings. For example, the term can apply to the failure of an electric circuit. Alternatively, it may refer to a rapid reduction in the resistance of an electrical insulator that can lead to aspark jumping [...]