Observation of the Peierls distortion in 3d doped Germanium lattice in the vicinity of the insulator-metal phase transition

A study of the electron spin resonance in Ge:As revealed that, in uncompensated semiconductors with shallow impurity levels, the insulator state is preserved near the insulator-metal phase transition because of the appearance of lattice distortions caused by interaction of spins localized on impurity atoms and the resulting spin-Peierls transition. In Ge:As, this effect is manifested at carrier concentrations n = 3 1017–3.7 1017 cm-3. Owing to the random distribution of impurities in the Ge lattice, the properties of this transition differ from those of a similar transition in substances in which uncompensated spins are localized on constituent ions of the host lattice.