화학공학소재연구정보센터
Materials Science Forum, Vol.517, 93-96, 2006
Structural, electrical properties and magnetoresistive effect in the (La1-xDyx)(0.67)Sr0.33MnO3 compound
The significant influences of substituting low concentration Dy at La- site for oF La0.667Sr0.333MnO3 perovskites compounds in structural, electrical and magnetoresistance properties have been studied. The polycrystalline samples (La1-xDy)(0.667)Sr0.333MnO3 with x = 0.00, 0.02 and 0.10 were synthesized via conventional solid-state reaction in bulk. This work measured their resistivity properties with (below 1 Tesla) and without the presence of magnetic field (0 Tesla) as a function of temperature, microstructure and particle distribution and structural distortion using four point probe resistivity technique, X-ray diffractometer (XRD) and Atomic Force Microscope (AFM). The resistivity in applied magnetic field or so-called magnetoresistance ratio is defined as MR% = (Ro - R-H)/R-H X 100 was measured at 90K, 100K, 150K, 200K, 250K, 270K and 300K. The highest MR% values for x=0.00, 0.02 and 0.10 are 15.3%, 15.5% and 20.6% at 1 Tesla respectively. The metal-insulator transition temperature, TmIT correspond to > 300K, 298K and 230K of sample with x= 0.00, 0.02 and 0.10 respectively were observed from resistivity-temperature (R-T) curve.