Author/Authors :
Xia، نويسنده , , Z.C. and Chen، نويسنده , , L and Niu، نويسنده , , D.W. and Zheng، نويسنده , , Q.H. and Fang، نويسنده , , Z.H and Zhang، نويسنده , , G.H and Fen، نويسنده , , W and Zhang، نويسنده , , L.J. and Tang، نويسنده , , J and Liu، نويسنده , , L and Liu، نويسنده , , S and Tang، نويسنده , , C.Q and Yuan، نويسنده , , S.L، نويسنده ,
Abstract :
Two kinds of composites of La0.67Ca0.33MnO3/ZrO2 and La0.67Ca0.33MnO3/YSZ have been investigated, in which the heterogeneous oxide YSZ represents yttria-stabilized zirconia (8 mol% Y2O3 + 92 mol% ZrO2). Their transport properties are measured in a temperature range of 10–300 K and a magnetic field range of 0–3 T. With increase in ZrO2 doping level for the range of 0–2%, the metal–insulator transition temperature, TP, decreases, but TP increases with the doping level increase further for higher than 2%. Meanwhile, in the composite of La0.67Ca0.33MnO3/ZrO2, besides the intrinsic metal–insulator (ferromagnetic–paramagnetic) transition, a new kink and a widen transition temperature region are observed both in the temperature dependence of resistivity and magnetization curves. Compared to pure La0.67Ca0.33MnO3 and the composite of La0.67Ca0.33MnO3/YSZ, we assume that the different effects between ZrO2 and YSZ on transport behavior of La0.67Ca0.33MnO3 result mainly from their different chemical stability.
