MSE Fall Seminar Series: Bharat Jalan, University of Minnesota

Description

"Novel Approaches for Atomically Precise Synthesis of “Stubborn” Metal Oxides"

Bharat Jalan

Department of Chemical Engineering and Materials Science, University of Minnesota

Bharat Jalan

 

Our ability to synthesize atomically-precise materials has continued to drive modern technology and fundamental study. Consider an element of periodic table that is hard to oxidize and also difficult to evaporate. How do we then create atomically precise layers of such metals, metal oxides or their heterostructures? This has been a central question in the synthesis science for many decades. In this talk, I will present my group’s effort to address this question. By designing and adding organic ligands—combinations of carbon, hydrogen, and oxygen atoms—to these “stubborn” metals, we have shown substantially higher vapor pressure, making them easier to sublimate at lower temperatures while yielding thin films with superior quality and scalable rates. 

We show, for the first time, atomically-precise synthesis of Pt, RuO2, IrO2 and SrRuO3 films with the same ease and control as afforded by III-V molecular beam epitaxy (MBE). I will present a detailed MBE growth study combined with structural and transport characterizations. The effect of film thickness, orientation, strain, and defects such as cation vacancies on electronic properties will be discussed. I will also present our work on the development of radical-based MBE approach for alkaline stannate (BaSnO3 and SrSnO3) films as a high-mobility wide bandgap semiconductor. I will discuss their structure-defect-property relationships with the particular emphasis on controlling and understanding the role of intrinsic point defects on electronic properties. 

For Webinar information please contact Kyle Page (kmp265@cornell.edu)