Order parameters and hysteresis behavior of a ferromagnetic Blume–Capel thin film: The role of the crystal field interactions

As a complementary work of a recent study (Physica B 433 (2014) 96), ferromagnetic thin films in simple cubic lattice structure described by a spin-1 Blume–Capel Hamiltonian have been considered within the framework of effective-field theory (EFT). Thermal variations of bulk and surface order parameters (i.e. magnetization and quadrupolar moments), as well as hysteresis loops in the presence of modified surface interactions, and crystal fields have been examined. We have found that depending on the type of the phase transition (i.e. ordinary or extraordinary), bulk and surface order parameters may exhibit fairly non-monotonous and quite exotic profiles. Regarding the bulk and surface hysteresis loops, at a fixed set of system parameters, both the bulk and surface hysteresis loops exhibit the same coercivity whereas remanence of a bulk (surface) loop is greater than that of a surface (bulk) loop in ordinary (extraordinary) case.