Incommensurate structures in a two-subsystem partially frustrated ferrimagnet

A new incommensurate magnetic structure with a locally triangular orientation of spins has been proposed for a two-subsystem magnet with frustrated intersystem exchange and competition between exchanges in one of the subsystems. When the temperature is lowered, this structure appears from the antiferromagnetic state after a first-order phase transition. It transfers to the Yafet–Kittel triangular structure when the threshold conditions for the exchange interactions are fulfilled. An increase in the length of the frustrated exchange bonds leads to the appearance of an incommensurate phase with the local antiferromagnetic orientation of the sublattices in each subsystem between the commensurate antiferromagnetic and Yafet–Kittel phases.