Structural, magnetic and field-driven abrupt magnetocaloric properties of La1.4-xSmxCa1.6Mn2O7 Ruddlesden-Popper manganites

Evolution in the structural, magnetic and magnetocaloric (MCE) properties for a series of samarium (Sm) doped La1.4-xSmxCa1.6Mn2O7 (0.0 <= x <= 0.4) Ruddlesden-Popper manganites prepared by using the solid-state reaction method have been investigated. Structural refinement of XRD profiles established that the MnO6 octahedral structural units were distorted upon Sm-substitution. The effect of Sm-concentration on the microstructure was also very well observed in terms of increased average grain size and absolute density. Discrepancy in MCE parameters by implementing the conventional isothermal curve method was appeared which was resolved with a separate calorimetric method. The isothermal entropy change was enhanced from 2.52 J/kgK for x = 0.0 sample up to 4.61 J/kgK and 4.2 J/kgK for x = 0.1 and x = 0.2 samples respectively. The temperature averaged entropy change (TEC) was also remarkably improved from 4.04 J/kgK up to 8.5 J/kgK and 7.77 J/kgK for the same compounds respectively.