Microstructure analysis of electrospun La_0.8Sr_0.2MnO₃nanowires using electron microscopy and electron backscatter diffraction (EBSD)

The microstructural properties of electrospun La0.8Sr0.2MnO3 (LSMO) nanofibers were investigated using electron microscopy and electron backscatter diffraction (EBSD). By means of EBSD, it is possible to measure the crystallographic orientation of the LSMO grains within an individual nanofiber. As the LSMO grains within the nanofibers are in the 10-nm range, we employ here parts of the recently developed transmission Kikuchi diffraction technique in order to enhance the Kikuchi pattern quality to enable an automated mapping of the crystallographic data. The diffraction results demonstrate that the grain orientation is not random, but there is a texture induced by the shape of the polymer nanofiber formed after the electrospinning step. Within an individual nanofiber section, the dominating grain boundaries are high-angle ones, which play an important role in the current flow through the sample (low- and high field magnetoresistance). The data obtained allow further an analysis of the grain shape aspect ratio, and elucidate the grain and grain boundary arrangement within electrospun LSMO nanofibers.