Magnetic properties and magnetocaloric effects in Er_{1 - X}Gd_xCoAl intermetallic compounds

The magnetism and magnetocaloric effect in Er_{1 - x}Gd_xCoAl (x = 0, 0.1, 0.2, 0.4, 0.6, 0.8, 1) were investigated. The Er_{1 - x}Gd_xCoAl compounds were synthesized by arc melting. With the increasing Gd content, the Néel temperature (T_N) linearly increases from 14 K to 102 K, while the magnetic entropy change (-ΔS_M) tends to decrease nonmonotonously. Under the field change from 0 T to 5 T, the -ΔS_M of the compounds with x = 0.2-1 are stable around 10 J/kg •K, then a cooling platform between 20 K and 100 K can be formed by combining these compounds. For x = 0.6, 0.8, 1.0, the compounds undergo two successive magnetic transitions, one antiferromagnetism to ferromagnetism and the other ferromagnetism to paramagnetism, with increasing temperature. The two continuous magnetic transitions in this series are advantageous to broaden the temperature span of half-peak width (δT) in the -ΔS_M-T curve and improve the refrigeration capacity.