Effect of V doping on the electrical transport and magnetoresistance properties of La0.825Sr0.175MnO3 ceramics

La0.825Sr0.175Mn1-xVxO3 (x = 0.00-0.05) ceramics were prepared by sol-gel method. X-ray diffraction analysis illustrates that all samples are perovskite structure, no impurity phases were detected. SEM shows that the grains are closely connected. With increasing V doping level, the grain size decreased from 27.78 mu m (x = 0.00) to 11.23 mu m (x = 0.05), which results into the enhancement of grain boundary effect. The temperature dependence of resistivity shows that all samples exhibit typical insulator-metal transition. With V doping up to 0.01, temperature coefficient of resistivity (TCR) increases from 4.65% K-1 to 6.1% K-1, and the magnetoresistance (MR) value reaches 38.629%. The electrical and the magnetic properties of V-doped La0.825Sr0.175MnO3 present a complicated behavior with further doping of V. These findings indicate that the properties of manganites can be effectively and dramatically tailored by doping of Mn, which meantime facilitate the application of manganites in infrared detector and magnetic sensors.