Kolat, V. S.Kaya, A. O.Izgi, T.Gencer, H.Bayri, N.Atalay, S.2024-08-042024-08-0420101454-41641841-7132https://hdl.handle.net/11616/95048In this work, the magnetic and magnetocaloric properties of LaFe11.4S1.6-xGex (x = 0.05, 0.1 and 0.2) and La1-xBixFe11.4Si1.6 (x = 0, 0.1 and 0.2) compounds have been investigated. X-ray results indicate that the samples with lower Ge and Bi contents mainly consist of the NaZn13-type phase with a small amount of alpha-Fe impurity phase. The alpha-Fe impurity phase increases with increasing concentrations of Ge and Bi. The Curie temperature of the samples also increases slightly with increasing Ge and Bi contents. The spin-wave dispersion coefficient D, exchange constant J and average mean-square range of exchange interaction ()(1/2) have been calculated. The increase in Curie temperature is attributed to an increase in the average Fe-Fe distance and ferromagnetic interactions. The peak values of the magnetic entropy change vertical bar Delta S-m vertical bar are found to decrease with increasing Ge and Si contents. This is attributed to a change of the phase transition from first order to second order. The peak values of vertical bar Delta S-m vertical bar are 22.38 J/kg K for LaFe11.4Si1.6, 12.58 J/kg K for LaFe11.4Si1.5Ge0.1 and 14.25 J/kg K for La0.9Bi0.1Fe11.4Si1.6 at a magnetic field of 6 T.eninfo:eu-repo/semantics/closedAccessNaZn13-type intermetallics compoundsMagnetocaloric effectMagnetic entropy changeLaFeSiArticle125112911342-s2.0-77953069260Q4WOS:000279165400025Q4