Interplay between magnetic anisotropy and dipolar interaction in one-dimensional nanomagnets: Optimized magnetocaloric effect

The magnetocaloric effect (MCE) in one-dimensional (1D) magnetic nanostructures is optimized for a specific value of the magnetic field H* when applied perpendicularly to the longitudinal direction of the system. Our results reveal that H* corresponds to the saturation field, slightly above the transition from a magnetically stable dipolar-coupled configuration to an unstable one. This MCE-optimizing field explicitly depends on the characteristic magnetic parameters of the system, namely, saturation magnetization (MS) and anisotropy constant (K): H* is directly proportional to MS², and the anisotropy contribution is equal to the anisotropy field of the particles HA=2K/MS. Accordingly, the MCE in 1D nanomagnets can be directly tuned by a proper choice of the characteristic MS and K values of the materials.