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MATERIALS ENGINEERING

SEMINAR

“MEMS Actuator Based on Dopant-Driving Thin Film Perovskite Nickelate”

By

Chengzi Huang

Purdue MSE Ph.D. Preliminary Exam

Advisors: Professors Dana Weinstein and Shriram Ramanathan

ABSTRACT

Rare earth nickelate exhibits a series of fantastic properties based on its abnormal metal-insulator transition (MIT) phenomenon, which has attracted huge concerns from different areas since 1970s. Except for traditional thermally driven method for phase transition materials, electron doping is found to be another effective driving mechanism which origins from the strong correlation of electrons in the orbital of Ni²⁺ cation. Giant changes of resistivity and lattice parameter are observed during the phase transition. In this work, the crystal structures and phase transition mechanisms of perovskite nickelates is being discussed, and based on their performance, NdNiO₃ (NNO) is selected to be the core material for MicroElectroMechanical Systems (MEMS) actuators. Synthesis as well as characterization method are also introduced to further understand and utilize its unique properties in actuators. Traditional actuation materials are being discussed in details and are compared with NNO to give a better idea to estimate the performance of NNO actuator. Although there is no record of perovskite materials utilized in actuation area, NNO is a strong candidate based on its unique properties such as high induced strain, giant resistivity change, and fast phase transition speed. This study also offers us an opportunity to explore the mechanical properties of perovskite nickelates associated with the phase transition, and their application in MEMS.

Date: Friday, December 8, 2017

Time: 12:00 P.M.

Place: ARMS 3115