Structural transition and charge density waves in thin films

A special type of low-temperature structural transition occurs in thin, size-quantized films with a strong anisotropy of the Fermi curve (e.g., in Bi films). The lattice appears to be unstable for such films. The structural transition is accompanied by the appearance of charge density waves and is characterized by peculiar temperature and thickness dependences of the electron concentration. Experimental data can be explained by the present theory. The possibility of new experimental investigations is discussed.