Studies of the electroresistive properties of electronic oxides

In this paper we report on the non-linear voltage-current relationship of three doped lanthanum manganite compounds (La0.8Li0.2MnO3, La0.66Sr0.33MnO3 and La0.8Pb0.2MnO3) and three manganite cobaltite compounds (DyMn0.5Co0.5O3, HoMn0.5Co0.5O3 and NdMn0.5Co0.5O3). We compare and contrast the magnitude and temperature dependence of the non-linear behaviour, and suggest this behaviour may be largely due to phase separation in the compounds. We also compare the behaviour of single-crystal and polycrystalline bulk samples of lead-doped lanthanum manganite (La0.8Pb0.2MnO3), which provide evidence for grain boundaries playing an important role in the non-linear voltage-current relationships in certain compounds.