Effect of frustration near the magnetic-nonmagnetic transition

Abstract

Many different physical situations can be explained by the effect of frustration in systems close to the magnetic instability. We study this phenomenon within a Blume-Capel model on a triangular lattice, by numerical and analytical calculations. Complex magnetic ordered phases, including coexistence of magnetic and nonmagnetic sites, are obtained. The interesting dependence of the phase diagram with pressure, magnetic field, and temperature is discussed in connection with experimental results on R${\mathrm{Mn}}_{2}$ systems.