Magnetocaloric effect on iron-based alloys

The magnetocaloric properties of magnetic materials are of great importance in terms of engineering and technology applications. Although it is quite remarkable for scientists that the magnetocaloric effect has a great potential in environmentally friendly heating and cooling technologies and biomedical applications; It has been extensively studied experimentally and theoretically by researchers. As a matter of fact, with some limitations of the studies; It has been pointed out that not only the large magnetic entropy change but also the cooling capacity is important in the application as a cooling material in terms of high cooling effect. Accordingly, in terms of cooling capacity, since materials with second-order magnetic phase transition show a relatively large magnetic entropy change over a wide temperature range, in this study, it was concluded that .Fe atoms of Al, Si, Ga, V, Mo, Nb, W, Zr, Co, Ni It is aimed to improve the Curie temperature and magnetocaloric properties by replacing it with many atoms such as Cr, Mn, Ni. For this purpose, direct and indirect measurements of Pr2Fe17-xCux (X=0, 0.1, 0.2) and Pr2Fe17-xTix (x = 0, 0.2, 0.4, 0.6) samples, which were prepared with high purity arc melting systematic and at stoichiometric ratios specified in the scope of the study, were investigated. It is aimed to contribute to magnetic cooling technology applications by examining the effects on the structural, magnetic and magnetocaloric properties of X-ray diffraction (XRD), scanning electron microscope (SEM) and magnetization measurements. Among the results obtained, SEM analyzes showed that the samples consisted of irregular shapes of micron-sized particles with a strong bond from 0.5μm to 4μm; EDX analyzes show that all samples are in single phase. However, all samples show transition from ferromagnetic to paramagnetic phase. In addition, while the Curie temperature increased for Cu and Ti added samples; The maximum entropy change for Cu added samples (x = 0, 0.1, 0.2) was determined as 5.63, 5.28 and 4.21 J/kg.K, respectively, and RCP as 404.8, 373.6, 288.3 (J/kg). The maximum entropy change for Ti added samples (x=0, 0.2, 0.4, 0.6), respectively, was 5.62, 4.75, 5.18, 4.28 (J/kg.K), RCP was 455.89, 415.22, 429.93, 362.59 (J/kg) ) was determined. Arrot plot curves and Landau analysis show that all samples are in second order phase transition. The results obtained in the study show that the produced samples are a potential magnetic coolant material. Keywords: Magnetocaloric Effect, Magnetic Cooling, Curie Temperature, Intermetallic Compounds