Sv. Dmitriev et al., DYNAMICS OF DOMAIN-WALLS IN AN INCOMMENSURATE PHASE NEAR THE LOCK-IN TRANSITION - ONE-DIMENSIONAL CRYSTAL MODEL, Physical review. B, Condensed matter, 55(13), 1997, pp. 8155-8164
A phase transition from a high-symmetry to a low-symmetry commensurate
phase through an incommensurate phase was studied in the framework of
the one-dimensional elastically hinged molecule model which includes
only a fourth-order anharmonic potential. The phase diagram with respe
ct to the harmonic-potential coefficient and the external force was ob
tained. From the numerical analysis of the equation of motion, it was
shown that the incommensurate phase near the lock-in transition contai
ns a periodic system of energetically equivalent domain walls which ar
e mutually repulsive. The properties of the domain walls were studied
and the lock-in transition was described as the annihilation process o
f the walls when the repulsion is changed to attraction.