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McKelvey School of Engineering

Brown School

"Design of Functional Perovskite Oxides from Atomistic Simulations, Machine Learning and Causal Analysis"

Thursday, November 16, 2023 | 3:00 PM - 4:00 PM

Stephen F. & Camilla T. Brauer Hall, 3015
6548 Forest Park Pkwy, St. Louis, MO 63112, USA

Dr. Saurabh Ghosh, Dept of Nuclear Engineering, University of Tennessee

The family of ABO3 perovskite oxides form a large class of compounds with diverse physical and electronic properties. This set of materials shows a wide range of functional properties, including ferroelectricity, ferromagnetism, multiferroicity, catalysis, radiation tolerance, etc. Single or multiple structural modes in bulk crystal materials can drive high symmetry to low symmetry phase transition. Coupling between structural modes can go two or more functional properties into the low symmetry phase. The celebrated Hybrid Improper Ferroelectricity (HIF) falls into this category of multimode-driven phase transition [1]. It has been reported to drive weak ferromagnetism, linear magnetoelectricity, and ferroelectricity into cation-ordered A/A systems with Pnma-ABO3 as building blocks [2].

 

In this talk [2-6], I will focus on how ABO3 oxides can be functionalized as (a) hybrid improper multiferroic and (b) nuclear energy material. I will discuss the emergent multiferroic properties by structural mode coupling considering (i) ABO3 / A’BO3 oxide superlattices and (ii) AA’BB’O6 double perovskites, where A and A’ are rare-earth or alkali metals and B, B’ are transition metals.  The aim is to establish meaningful cross-coupling between functional properties such as ferroelectricity, magnetism and metal-to-insulator transition. Understandings developed from first principles calculations, ab initio molecular dynamics (AIMD), and hypothesis-driven active machine learning (ML) will be presented. I will also discuss how we can go beyond the traditional correlative nature of ML models to establish a causal relationship between the descriptor space constructed from structural modes plus other geometry-driven features and target property, i.e., cation ordering in double perovskites For nuclear energy materials, the critical performance matrix is tolerance against radiation damage. I will briefly discuss how AIMD simulations and ML can help design potential ABO3 complex oxides for applying radiation shields and nuclear waste forms.

 

Faculty, students, and the general public are invited.

 

Hosted by: Rohan Mishra, MEMS

 

 

Event Type

Seminar/Colloquia

Schools

Arts & Sciences, McKelvey School of Engineering

Topic

Science & Technology

Website

https://imse.wustl.edu/

Department
Institute of Materials Science & Engineering, Mechanical Engineering & Materials Science
Event Contact

Beth Gartin, bgartin@wustl.edu

Speaker Information

 Dr. Saurabh Ghosh joined the Department of Physics and Nanotechnology, SRM Institute of Science and Teleology, Tamil Nadu, India, as an Assistant Professor (Research) in June 2017. Now, he works as an Associate Professor (Research) in the same department.

Dr. Ghosh completed his doctoral work at the Indian Association for the Cultivation of Science, Kolkata and earned his PhD from Jadavpur University, Kolkata, West Bengal, India, in 2011. Before joining SRM, he worked as a postdoctoral researcher in the USA from April 2011 to May 2017 at Cornell University, Ithaca, NY and then at Vanderbilt University, Nashville, TN /Oak Ridge National Laboratory, Nashville, TN.

In SRM, he has formed and, at present, is leading the ‘Functional Materials by Design’ (FMD) group. The objective of the FMD group is to design functional materials from first-principles Density Functional Theory (DFT) calculation, Ab initio molecular dynamics (AIMD) and Machine Learning (ML), guided by group theoretical techniques and supported by phenomenological models.  Understanding a material's ‘structure-property’ relation is key in designing new materials. The group is focused on developing functional materials by tailoring ‘structure-properties’ relations that impact oxide electronics, spintronics, and energy research. The FMD group is forming strong collaborations with other experimental and theory groups (in the USA, Sweden, Italy, Singapore and India) for research activities. The group is productive in publishing high-quality journal papers, i.e., in Phys. Rev. Lett., Nature Communication, Phys. Rev. B., Chemistry of Materials, etc. and funded by various funding schemes by the Government of India. Two PhD scholars have successfully graduated from the FMD group, and one is now working as a postdoc in the US. Dr . Ghosh has given over 40 invited talks. He is the convener of the international workshop and conference “Evolution of Electronic Structure Theory and Experimental Realization (EESTER)”, jointly organised by SRMIST and IIT Madras in India every two years, and that is one of the leading workshops and conferences in India.

Currently, Dr Ghosh is on sabbatical leave and visiting as a scientist in the Dept. of Nuclear Engineering, University of Tennessee Knoxville, Knoxville, USA, with host Prof. Brian D. Wirth, Governor’s Chair Professor, University of Tennessee, Knoxville, USA, and working on "machine learning on nuclear materials

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