Magnetic And Magneto-Thermal Properties Of Ferrimagnetic Alloys (Er1-X Y X )(Co0.84fe0.16)(2) And Their Dependence On The Orientations Of Resultant And Sublattice Magnetizations

In this paper structure, magnetic and magneto-thermal properties: magnetic entropy change (Delta S (m)) and refrigeration capacity (q) of Er1-x Y x (Co0.84Fe0.16)(2) alloys (x = 0, 0.2, 0.4, 0.6, 0.8, 1) in magnetic fields up to 90 kOe in a temperature range of 5-360 K are investigated. An analysis of temperature dependences of magnetization (sigma) and high-field susceptibility (chi (hf)) showed that in these compounds, three different ferri- and a one ferromagnetic structures are consequently realized. Concentration dependences of magnetic moment at 5 K (mu (f.u.)), Curie temperature (T (C)), residual magnetization (sigma (r)) and coercivity (H (c)) have been shown to have an extreme at intermediate Y concentration. The character of temperature dependence of magnetic entropy change (Delta S (m)(T)) depends on the composition and originates from the type of magnetic structure of the compound and the mutual orientation of R- and 3d- element sublattices magnetization with respect to the resulting one. In compounds with x = 0.6 and x = 0.8 temperature regions with different signs of Delta S (m) are observed, reflecting the change of dominating R- or 3d- sublattice in the resulting magnetization.