It can be determined from the way the polycrystalline solid has grown or by the processing conditions. In these, the order and the orientation are very random. For example, all the metals and ceramics are polycrystalline. Therefore, in a polycrystalline structure, the long-range order has been disrupted. That is, it does not have long-range, ordered arrangement of atoms, molecules, or ions within the structure. Amorphous solid is a solid, which lacks a crystalline structure. In a structure like this, number of single crystals is held together by a layer of amorphous solids. Most of the time solids are polycrystalline. There are solids, which are composed of a single crystal like gems and silicon single crystals, but these occur very rarely in nature. The crystals in a polycrystalline solid are microscopic, and they are known as crystallites. These are arranged in different orientations and are bound by highly defective boundaries. Polycrystalline are solids that are composed of many numbers of small crystals. In nature, most of the time, crystals appear to have disrupted their long-range order. Crystals have an aesthetic value, and it is believed to have healing properties thus, people use them to make jewelry. Crystals can have different shapes and colors. sodium chloride), and molecular crystals (e.g. Crystals can be categorized according to their physical and chemical properties. There are water-based crystals in the form of snow, ice, or glaciers. For example, calcite is produced by mollusks. Crystals are formed by living organisms too. However, crystals are not restricted to minerals: they comprise most solid matter such as sugar, cellulose, metals, bones and even DNA.” Crystals are naturally occurring on earth as large crystalline rocks, such as quartz, granite. Examples are halite, salt (NaCl), and quartz (SiO 2). By definition, “a crystal is a homogenous chemical compound with a regular and periodic arrangement of atoms. In crystalline solids, there is a regular, repeating pattern thus, we can identify a repeating unit. The atoms, molecules, or ions in crystals are arranged in a particular manner, thus have a long-range order. Crystalline solids or crystals have ordered structures and symmetry. Crystalline is being a crystal, composed of crystal or resemble a crystal.
0 kommentar(er)
