MSE Seminar: Manisha Dixit, Structure-Property Correlations in Double Perovskite Systems

PhD Candidate advised by Dr. Hamish Fraser, Department of Materials Science and Engineering, The Ohio State University

Abstract

Double perovskite compounds of the type ABB’O₃ where B and B’ are transition elements, exhibit a wide range of properties that are useful for various applications. Double perovskites such as Sr₂FeMoO₆ (SFMO), Sr₂CrReO₆ (SCRO) are ferrimagnetic materials with properties useful for spintronic applications. The ordering of Fe and Mo atoms in the case of SFMO and Cr and Re atoms in case of SCRO known as B-site ordering is very important. Sputter-deposited thin-films of SFMO and SCRO systems were characterized using various high resolution transmission electron microscopy (TEM) techniques.

B-site disorders, other kinds of structural defects and variation in chemical composition were found in the thin-films studied. Valence state of Fe in SFMO system was studied using electron energy-loss spectroscopy (EELS). In order to interpret the EELS data, other comparative perovskite compounds were also utilized. In the case of SCRO system, multislice simulations were used to interpret information about B-site ordering from scanning transmission electron microscopy images acquired using the high-angle annular dark-field detector. It was found that presence of various kinds of structural defects and composition variations in these systems have an effect on the useful magnetic and electrical properties.

Bio

Manisha Dixit has a BS degree in Metallurgical Engineering from India. She worked for Tata Steel for about two years before moving to US to pursue higher studies. After completing her MS in Materials Science and Engineering from Missouri University of Science and Technology-Rolla, she started her doctoral studies at The Ohio State University. In her free time she likes making crafts and spending time with her family.