Scaling of magnetic entropy change and anomalous magnetic correlations in ternary alloy Ce1.3Pr0.7Co7

摘要

We have studied the magnetic coupling property, magnetic entropy change, and magnetic phase transition behavior of ternary alloy Ce1.3Pr0.7Co7. It exhibits a typical paramagnetic-ferromagnetic phase transition at TC = 218 K and this phase transition is verified to be second order by the scaling theory. Based on the data of isothermal magnetization measured around TC, we obtained the variation of its magnetic entropy change under the different magnetic fields but it only shows a smaller entropy change value. Density functional calculations confirm that the extra magnetic interaction originates from the Pr-Pr exchange interactions, which yields anomalous magnetic coupling with Co-Co (Ce-Ce) exchange interactions. One phenomenological model is suggested to understand anomalous magnetic behavior observed in the present intermetallic compounds.