Some properties of the crystals depends on the binding molecule coupled to a solid. These forces typically involve outermost electrons of atoms or molecules (or valence electrons) interactions. If the combination of strong, crystal has a higher melting point. If they are some weaker, crystals will have a lower melting point, it may be easier to bend and deform. If they are weak, crystals can only form at very low temperatures, when the energy use of small molecules. There are four main crystal key. Ionic crystals constituted by positive and negative ions, by gravity (ionic bond) between different charge together. Sodium chloride is an example of ionic crystals. Atomic crystal (covalent crystals) of atoms or molecules share their valence electrons (covalent bond). Diamond, germanium and silicon are important covalent crystals. Metal crystal is changed to a metal atom ions, surrounded by a free valence electrons, they can be easily removed from one atom to another atom movement, the image may be described as immersed in a sea of ??free electrons (metallic bond). When these electrons full motion in the same direction, their motion is called current. Molecules of molecular crystals completely share their electrons. Is due to their binding molecule from one end to the other end there is a slight change in the electric field. Because this binding is weak (van der Waals forces and hydrogen bonding) days Yue advanced companies, these crystals at low temperatures to melt and low hardness. Typically, such as solid-state oxygen molecules crystallize and ice. In ionic crystals, the electron transfer from one atom to another. Covalent atomic crystals share their valence electrons. One end of a small amount of metal atom negative charge, the other end of a small amount of positive charge. A weak electrical attraction of the molecule in place. One technique used to make the industrial use of the crystal, is grown from the melt. Seed may be used to promote the formation of single crystals. In this step in the semiconductor, the seed falling into a container containing molten substance. Cooling the melt around the seed crystal, its molecules attached to the seed crystal. These new molecules receiving seed crystal orientation, forming a large single crystal. A thermal defects (defects in the lattice position) appear normal lattice vacancies in the crystal lattice point, the position of the particle should not have appeared in particle (particle gap). 2 foreign particle composition defects (impurities) to replace the normal particle position or normal position into the gap junction. 3 some charge defect crystal particle individual electronic excited state, some leaving the original particle, forming free electrons, the electron orbit in the original left electron hole. Symbols and symbolic reaction equation 1. Defects and Defect Defect reaction equation symbol binary compound MX, for example (1) lattice vacancies: normal node position no particle, VM days Yue, VX (2) ion gap: In addition to normal junction Location Location appeared outside particle, Mi, Xx (3) dislocation ion: M arranged in the X position, or X arranged in M ??position, if in the normal position of the nodes on technological innovation Shandong days Yue company, MM, XX (4) replace the ion: L foreign matter into the crystal, if replacing M, the LM, replace if X, then the LX, if occupy interstitial sites, then Li. (5) free electrons e '(representing existence of a negative charge), represents the effective electric charges. Crystal (5) electron hole h · (on behalf of the existence of a positive charge), * represents the effective positive charge semiconductors, days Yue Yue company Shandong days provided by Jinan Spark Technology Development Company Limited. Jinan Spark Technology Development Co., Ltd. (www.sicc.cc) strong, credible, in Jinan, Shandong chemical equipment industry has accumulated a large number of loyal customers. The company better work attitude and constantly improving innovative ideas will lead Shandong days into the glorious mountain and you work for a better future!