Structural and Electrical Properties of Nd-Doped (La,Sr)MnO3 Bulk Ceramics

Abstract

(La0.7-xNdxSr0.3)MnO3 (x = 0.15-0.3) specimens were prepared using the mixed oxide method. All specimens showed an orthorhombic crystalline structure and exhibited microstructures with sub-mu m sized grains and pores. According to XPS analysis, Mn2+, Mn3+ and Mn4+ ions peaks corresponded with binding energies of 640.6-640.9 eV, 642.0-642.4 eV, and 643.4-644.1 eV, respectively. Mn ions were predominantly in Mn2+ and Mn3+ states. All specimens exhibited a negative temperature coefficient of resistance (NTCR), in which the resistance decreased linearly as the temperature increased. Resistivity increased with the amount of Nd. The 0.3 mol Nd doped LSMO specimen showed 2.85 x 10(4) omega cm, the highest value of resistance. The 0.2 mol Nd-doped LSMO specimen showed the highest TCR value, which was - 0.36%/degrees C, and a B-25/65 value of 366 K.