Poolkristalliline

Poolkristalliline refers to a class of materials that possess a structure intermediate between fully crystalline and fully amorphous solids. In such materials, regions of ordered crystalline structure are interspersed with regions that lack long-range order, characteristic of amorphous materials. These ordered regions are often referred to as crystallites or grains. The size of these crystallites can vary significantly, from nanometers to micrometers.

The properties of poolkristalliline materials are a consequence of this mixed structure. They typically exhibit characteristics that are a blend of their crystalline and amorphous counterparts. For example, their mechanical strength and stiffness may be higher than amorphous materials due to the presence of crystalline phases, but they might also possess some degree of toughness and ductility that is less common in highly crystalline solids. Their optical and thermal properties are also influenced by this heterogeneity.

Common examples of poolkristalliline materials include many polymers, such as polyethylene and polypropylene, where the degree of crystallinity can be controlled during processing to tailor their properties. Certain ceramics and some metals can also exhibit poolkristalliline structures, depending on their formation and processing conditions. The proportion of crystalline material within the sample, known as the degree of crystallinity, is a critical parameter that dictates the material's overall behavior and performance in various applications.