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Manisha Dixit

  • 2041 College Rd
    Columbus, OH 43210

About

Manisha's current research involves study of perovskite materials such as Sr2FeMoO6, and Sr2CrReO6 that are useful materials for spintronic applications. She has been using various high-resolution transmission electron microscopy (TEM) techniques to study and characterize TEM foils, sectioned along specific crystallographic directions using dual-beam focused ion beam (FIB) technique. These techniques include imaging using scanning transmission electron microscopy (STEM) in the high-angle annular dark-field mode (HAADF). The atomic resolution imaging of defect-free regions and various defects are complemented with high resolution energy dispersive X-ray spectroscopy (EDS) that includes FEI ChemiSTEM™ technology and electron energy-loss spectroscopy (EELS) to characterize chemical composition, nature of chemical bonding and electronic band structure. Such comprehensive studies help to investigate the effect of defects on the useful magnetic properties in spintronic materials.

STEM-HAADF images are being simulated using multislice simulations to interpret intensities and structure correctly. She has also been complementing these studies with ab-initio simulations using density functional theory (DFT) calculations as implemented in Vienna Ab-initio Simulation Package (VASP). Results of the electronic structure that have been obtained using ab-initio calculations compare well with the experimentally acquired data and help in the interpretation of EELS spectra. A combined use of several TEM based techniques has helped to develop a comprehensive understanding about these perovskite materials.

Figure - STEM-HAADF image gathered on Titan 80-300™. Illustrates the presence of Sr-rich linear defects and iron-rich ovular defects in a (111) grown Sr2FeMoO6 thin film sputter deposited on (111) SrTiO3 substrate