Session: 16-01-01: Government Agency Student Poster Competition

Paper Number: 149947

149947 - Synthesis of Multi-Principal Element Silicide Thin Films Using Pulsed Laser Deposition 

The objective of this work is to develop a fundamental understanding of the thermophysical properties of multi-principal element silicides (ME-silicides). ME-silicides are a newly discovered family of ceramics that typically consist of five or more elements in the same lattice site of an atomic structure, and are being explored as environmentally stable, radiation-resistant thermal barrier coatings. These ceramic materials offer microstructural stability and superior mechanical properties at high temperatures. ME-silicides are extremely versatile and promising and are being explored as next-generation environmental barrier coatings to protect substrate alloys against oxidation in extreme environments. These environments include rocket nozzles, combustion chambers, and other propulsion components for on and off-planet vehicles, improving efficiency and performance. Additionally, ME-silicides could be used to protect against the harsh environment of space and various planetary environments due to their high-temperature resistance. They are also being explored for their protection from high-energy ion irradiation and their ability to withstand extended exposure without exhibiting a phase change. The critical challenge in achieving this objective is understanding the underlying mechanisms of silicide formation leading to the synthesizing of high-quality ME-silicides. To address this challenge, we investigate the thin film formation of (NiCoCrFeMn)Si2, a five-cation element silicide system, in this study. Using pulse laser deposition, we deposit sub-100 nm thin films of equiatomic NiCoCrFeMn onto a Si substrate in an ultra-high vacuum environment. We have chosen silicon as our substrate due to issues with silicide thin films not adhering to surfaces, making the substrate necessary for the thin film to diffuse into to make the silicide. As we anneal the thin films at high temperatures (500–800 °C) in a vacuum, we investigate the interdiffusion and chemical reactions between the substrate Si and the elements of the thin films, leading to ME-silicide formation. In the ME-silicides made with this method, we determine the thin films' crystal structure and elemental homogeneity at various deposition parameters and heat treatments. We will characterize our samples and determine the quality of the silicide based on data collected from several experiments such as X-ray diffraction, atomic force microscopy, and transmission electron microscopy. This gives us the ability to determine phase, crystal structure, surface roughness/durability, film thickness, interface properties, atomic structure, and elemental distribution. Thermal expansion and conductivity experiments will also be conducted to assess the interfacial bonding of the film/substrate interface. We hypothesize that we can make high-quality ME-silicides, and the coexistence of selected multiple elements at one cationic site in entropy-stabilized ME-silicides will create diverse bonds from contributing cation elements. These diverse bonds will significantly modify the characteristic electronic structure and enhance high-temperature oxidation and radiation resistance.

Presenting Author: Lance Spiegel Oklahoma State University

Presenting Author Biography: My name is Lance Aaron Spiegel. I was born in 2004 and raised in Mustang, Oklahoma. From a young age, I excelled in math and science, which inspired me to pursue a career in engineering. To prepare for college, I took AP courses and classes at Oklahoma State University – OKC. After careful consideration, I decided that Oklahoma State University was the best fit for me to study Mechanical and Aerospace Engineering. With hard work and dedication, I earned a spot in Oklahoma State University’s honors college. This opportunity opened several doors for me, providing rare research opportunities under Dr. Sachan and alongside his graduate students. Through this experience, I have gained valuable knowledge that goes beyond the typical classroom setting. I plan to continue pushing myself beyond the expectations of an undergraduate, learning from both my peers and professors, and striving for excellence in my field.

Authors:

Lance Spiegel Oklahoma State University
Joshua Marvin Oklahoma State University
Vikas Paduri Oklahoma State University
Ronald Noebe Glenn Research Center
Ritesh Sachan Oklahoma State University