| Manganites with porverskite structures have attracted researchers'attention not only because their wide prospect of application in electron spin devices, but also they provide platforms for basic research. In this thesis, we prepare hole-doped and electrons-doped manganites by pechini process, and investigate their physical properties systematically.LCMO/AlO/Al tunnel junction was fabricated with magnetic sputtering technology on the LCMO bulk with good connectivity between grain boundaries which was sufficiently polished. Temperature dependence of density of states (DOS) was investigated via the dI/dV-V curve. It was found that far below the courier temperature the DOS had stronger dependence on energy than that for temperature near and above courier temperature. We fitted the tunneling conductance near the Fermi-level with the equation , the results shows that the system reveals good metallic property and the effect of electron-electron interaction can be quite prominent.Nd1-xZrxMnO3 and Pr1-xZrxMnO3 compounds was successfully synthesized by sol-gel process, the x-ray photoemission spectroscopy investigation shows that, the Mn cations of the sample are in the divalent and trivalent states after Zr was introduced means that the systems were electron doped. In addition, for Nd1-xZrxMnO3, the M-T curve during both ZFC and FC process shows negative magnetization, which was also called magnetic reversal .In comparison, Pr, being similar with Nd, which belongs to the light thulium material, has no sign of magnetic reversal in higher temperature region. Combining the previous study, we proposed that the appearance of magnetic reversal during the higher temperature region was result from the competition between two antiferromagnetic coupled lattices Mn2+/Mn3+ and Mn3+/Mn3+, while in low temperature region It may related with the ordering of Nd3+ ions .and the peak of the specific heat in low temperature provides an effective evidence for the ordering of Nd3+ ions in low temperature.
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