Magnetic and Magnetocaloric Properties of Multiferroic Oxides Gd<inf>0.5</inf>Y<inf>0.5</inf>MnO<inf>3</inf>and Eu<inf>0.5</inf>Dy<inf>0.5</inf>MnO<inf>3</inf>

In this article, crystal structure, magnetism, heat capacity, magnetocaloric effect (MCE), and electrical resistivity of mixed rare-earth Gd0.5Y0.5MnO3 and Eu0.5Dy0.5MnO3 manganites have been studied. Temperature-dependent magnetization M(T) measurements suggest an antiferromagnetic order just below 6 K in Gd0.5Y0.5MnO3, while no magnetic transition has been observed down to 5 K in Eu0.5Dy0.5MnO3. Heat capacity data reveal anomalies at 40 and 42 K in Gd0.5Y0.5MnO3 and Eu0.5Dy0.5MnO3, and these may correspond to Mn magnetic order as previously reported. The magnetization values are 2.8 and 3~mu -{mathrm {B}} /f.u. in 70 kOe field at 5 K for Gd0.5Y0.5MnO3 and Eu0.5Dy0.5MnO3, respectively. MCE has been estimated in terms of isothermal magnetic entropy change (Delta S-{mathrm {m}} ) at low temperatures. The maximum values of Delta S-{mathrm {m}} are about -11 and -6.2 J kg {-1},,text{K}{-1} , respectively, for Gd0.5Y0.5MnO3 and Eu0.5Dy0.5MnO3 samples for a field change of 70 kOe at 8 K. Electrical resistivity of Gd0.5Y0.5MnO3 and Eu0.5Dy0.5MnO3 shows variable range polaron hopping behavior in the temperature range of 210-350 K.