Spin-Peierls transition in the Ge:As semiconductor impurity system in the vicinity of the insulator-metal phase transition

The effect of an elastic spontaneous distortion of the crystal lattice of a doped semiconductor Ge:As was observed near the insulator-metal (IM) phase transition. The effect was discovered in a study of the electron spin resonance at electron concentrations 0.8≤n/nC≤1 (nC=3.7x1017 cm-3 is the critical electron density for the IM phase transition) at low temperatures T≤100 K. A study demonstrated that the phenomenon can be understood in terms of the Peierls model of a spin transition in the disordered spin system of the semiconductor. The spin-Peierls transition gives rise to a new type of defects in doped uncompensated or weakly compensated n-type semiconductor in the form of a domain structure.