chemical order/disorder

An order about the arrangement of constituent elements in a compound or an alloy. For example, in the case of a compound containing two atoms A and B, a "chemical order" implies that each atom is alternately arranged in an ordered fashion. When each atom is arranged in a random fashion, this state is called a "chemical disorder." The chemical disorder takes place when the chemical properties of the constituent atoms are similar to each other. Compounds or alloys can take a chemical disorder state at high temperature and undergo a chemical order state at low temperature.