Room temperature properties of microstructure and resistivity of alkaline earth – doped on lanthanide manganite

Abstract

Microstructure of material has a strong relation with resistivity property. Here we report our interesting sample of La0.7(Sr1-xBax)0.3MnO3 (x = 0, 0.3, 0.6, and 0.9) material that has been synthesized by using sol-gel method successfully. All pattern of X-ray diffractometer (XRD) on the successful samples show that all samples are single phase confirmed without significant crystal disorder. The XRD pattern refinement yield that all samples formed R-3c space group with a rhombohedral structure. Although the substitution of Ba2+ to Sr2+ ions have significant difference in atomic radius; it does not change the crystal structure. However, the alkaline earth – doped on lanthanide manganite causes a change in lattice parameters which is followed by shifted of average crystal size, bond length, cell unit volume and bond angle at Mn-O-Mn. The microstructure results by means of scanning electron microscope (SEM) characterization shows that substitution of Ba2+ ions decrease the grain size and yield agglomeration. The relation on the microscopic result resistively confirmed by cryogenic magnetometer characterization in the concentration x = 0 has minimum resistivity of 1.28.10-3 Ωm and the maximum resistivity in the concentration x = 0.9 is 1.85.10-1 Ωm. The Ba2+ doped into Sr2+ in lanthanum manganite may cause a wider resistivity range.

Keywords

• manganite perovskite
• sol-gel
• grain size
• resistivity