Magneto-elastic phase transitions in one-dimensional systems

Abstract

The magneto-elastic phase diagram in one-dimensional systems relating to the interplaybetween magnetism and lattice distortion is studied in a double-exchange andsuper-exchange model considering classical localized spins and the limit of large Hund’scoupling. At low super-exchange interaction energy, a phase transition occurs betweenelectron-full ferromagnetic distorted and electron-empty antiferromagnetic undistortedphases via phase separation. In this case, all electrons and lattice distortions are foundwithin the ferromagnetic domain. For higher super-exchange interaction energy,phase separations consisting of two- or three-site distorted independent magneticpolarons separated by electron-empty undistorted antiferromagnetic links areobtained. In this regime, each polaron contains an electron, leading to a Wignercrystallization. The lattice distortion and charge distribution inside the polarons are alsocalculated.