Microstructure and Magnetocaloric Effect of Gd-La-AI Alloy
Taking Gd3-xLaxAl2(x=0,0.1,0.2,0.3)magnetic refrigeration materials as the research object,the phase composition,microstructure and magnetocaloric properties were systematically analyzed.The results show that all Gd3-xLa-xAl2(x=0,0.1,0.2,0.3)alloys are composed of Gd3Al2 phase,GdAl phase and Gd2Al phase.La atoms are mainly distributed in Gd2Al phase and the addition of La can regulate the morphology of GdAl phase.The Curie temperature TC of Gd3-xLaxAl2(x=0,0.1,0.2,0.3)alloys decreases gradually with the in-crease of La content,which is 275,267,261 and 252 K,respectively.The magnetic transition characteristics of Gd3-xLaxAl2(x=0,0.1,0.2,0.3)alloys were analyzed by Landau theory.The fitting results show that Gd3-xLaxAl2(x=0,0.1,0.2,0.3)alloys have the advantage of low hysteresis due to second-order magnetic phase transition near Curie temperature TC.The maximum isothermal magnetic entropy change(△SM)max of Gd3Al2 alloy is 3.05 J·kg-1·K-1,and the maximum adiabatic temperature change(△Tad)max is 2.12 K,showing excellent magnetocalo-ric properties.
magnetic refrigeration materialmicrostructuremagnetic phase transitionmagnetocaloric propertiesrare earths