Final Defense: Jianan Shen

Event Date: June 27, 2024
Time: 2:00pm
Location: ARMS 3115 or via WebEx
Priority: No
School or Program: Materials Engineering
College Calendar: Show

"Bismuth-Based Layered Supercell Multiferroic Thin Films Towards Multifunctionality and Device Applications" 

Jianan Shen, MSE PhD Candidate 

Advisor: Professor Haiyan Wang

WebEx Link


Multiferroics, which exhibit multiple ferroic orderings within a single material system, have substantial potential for applications in sensors, transducers, memory devices, and energy harvesters. However, the development of single-phase multiferroics that demonstrate room-temperature properties remains limited by inherent contradictions in d-orbital occupancy between magnetic and ferroelectric materials. This dissertation work focuses on addressing this challenge through the exploration of a novel bismuth-based, single-phase multiferroic thin film that features an exotic layered supercell (LSC) structure and displays multiferroic properties at room temperature. The primary aim is to deepen the understanding of LSC materials and advance their applications in practical devices. The core of the dissertation research comprises four chapters that present a comprehensive study of LSC materials. The first chapter discusses a nanocomposite system combining an LSC material, Bi1.25AlMnO3.25, with Au nanoparticles, highlighting its tunable microstructure and multifunctional properties influenced by growth temperature. The second chapter explores the integration of Bi2NiMnO6 on a flexible mica substrate, demonstrating the potential of LSC materials for use in flexible electronics, with performance maintained across various bending conditions. The third chapter details the development of freestanding LSC thin films using a water-soluble sacrificial layer, which are shown to preserve their microstructure and properties after being transferred onto a silicon substrate. Building on this, the fourth chapter investigates the reuse of recycled SrTiO3 substrates for subsequent thin film growth, examining changes in surface strain
states and chemistry to guide sustainable practices in complex oxide thin film processing. In summary, this dissertation presents an extensive examination of LSC multiferroics, revealing their significant promise for multifunctional applications and integration into flexible and silicon-based electronics. Additionally, the work explores sustainable methods for substrate reuse, contributing further to the field of material sciences.

2024-06-27 14:00:00 2024-06-27 15:00:00 America/Indiana/Indianapolis Final Defense: Jianan Shen ARMS 3115 or via WebEx