Spin-polarons in an exchange model

Abstract

Spin-polarons are obtained using an Ising-like exchange model consisting of double and super-exchange interactions in low dimensional systems. At zero temperature, a new phase separation between small magnetic polarons, one conduction electron self-trapped in a magnetic domain of two or three sites, and the anti-ferromagnetic phase was previously reported. On the other hand the important effect of temperature was missed. Temperature diminishes Boltzmann probability allowing excited states in the system. Static magnetic susceptibility and short-range spin-spin correlations at zero magnetic field were calculated to explore the spin-polaron formation. At high temperature Curie-Weiss behavior is obtained and compared with the Curie-like behavior observed in a nickelate one-dimensional compound.