Natural pinning field effecting on one surface of C60-like-nanostructure antiferromagnetic mixed-spin (1/2, 1) Ising spin system

Abstract

Based on magnetic phenomena at the interface in metal-C60 bilayer or multilayer film, we construct a natural pinning field effecting on one surface of C60-like-nanostructure antiferromagnetic mixed-spin (1/2, 1) Ising spin system. By use of the decoration transformation and the transfer matrix method, we found that the ground states, magnetic susceptibility, magnetization behavior and specific heat of the system display various unique properties. Eight ground state phases with different values of magnetization are shown in the parameter space of single-ion anisotropy and pinning field, and at some certain boundary between two phases, the magnetic susceptibility multiplied by temperature is a non-zero finite value at the zero-temperature limit. The specific heat curve appears double-peak phenomena, a sharp peak and a round peak respectively. The entropy of the system exactly shows considerable serried excited states adjacent to the ground state of the system with temperature increasing from zero, explaining why there is a sharp peak of specific heat at ultra-low temperature. This study can offer a reasonable theoretical explanation for unique magnetic phenomena at interface in metal-C60 bilayer or multilayer.