The development of new materials showing the magneto-caloric effect (MCE) requires fast and reliable characterization methods. For this purpose, a phenomenological model developed by M. A. Hamad has proven to be a useful tool to predict the magnetocaloric properties (the isothermal magnetic entropy change, \(\Delta S_\textrm{M}\) , the magnetization-related change of the specific heat, \(\Delta C_{P,H}\) , and the relative cooling power, RCP) via calculation from magnetization measurements as a function of temperature, M(T). However, fitting the M(T) data is difficult for broad, smoothed-out transition curves which are often observed for material systems such as core-shell nanoparticles, nanowires, nanowire fabrics or nanoparticle hybrid materials. Thus, in this contribution we present a different approach enabling proper fitting of such magnetization data via the use of an asymmetric Boltzmann sigmoid function, which provides a clear physical background and enables to properly describe the broad and smoothed out transitions of nanomaterials. As examples for our procedure, we present fits to M(T) curves of polycrystalline, bulk \(\hbox {La}_{0.67}\hbox {Ba}_{0.33}\hbox {MnO}_3\) as well as \(\hbox {La}_{1-x}\hbox {Sr}_{x}\hbox {MnO}_3\) ( \(x=\) 0.2, 0.3, 0.4) and \(\hbox {La}_{0.7}\hbox {Ca}_{0.3}\hbox {MnO}_3\) nanostructured materials from various authors.
