epäkiteiset

Epäkiteiset is a Finnish term that translates to "amorphous" or "non-crystalline" in English. It refers to materials that lack a long-range, ordered atomic or molecular structure. Unlike crystalline materials, where atoms are arranged in a regular, repeating lattice, amorphous solids exhibit a disordered, random arrangement of their constituent particles.

Examples of epäkiteiset materials include many common substances. Glass, for instance, is a well-known amorphous solid. Polymers, such as plastics, are often amorphous, though some can have semi-crystalline regions. Certain metals and alloys can also be prepared in an amorphous state, often referred to as metallic glasses. Other examples include amorphous silicon, used in solar cells, and amorphous carbon, found in various applications.

The properties of epäkiteiset materials can differ significantly from their crystalline counterparts. For example, amorphous materials often exhibit isotropic properties, meaning they are the same in all directions. They may also have different mechanical, optical, and electrical characteristics. The absence of grain boundaries, which are present in crystalline materials, can lead to enhanced corrosion resistance in some amorphous metals. The disordered structure also means that amorphous solids do not have sharp melting points; instead, they soften gradually over a range of temperatures. The term is primarily used in materials science and solid-state physics.