Orbital structure and magnetic phase diagram of the four-sublattice ferromagnet PbMnBO4

https://doi.org/10.1016/j.jmmm.2023.170520

A role of quadric and quartic single-ion anisotropy (SIA) of Mn³⁺-ions, dipole–dipole and Dzyaloshinsky–Moriya (DM) interactions for the magnetic ordering of the four-sublattice ferromagnet PbMnBO₄ is investigated. A phase diagram of low-lying magnetic phases on the plane of the DM exchange components is obtained for different values of the SIA parameters. An effect of the isotropic interchain exchange on the spin orientation and, as a result, on the SIA energy in different magnetic phases is considered at the comparable values of the interactions. The determinative role of DM exchange for the magnetic anisotropy of PbMnBO₄ is discussed.