Faculty, Student Research on Strengthening Ceramics Published in Top-Tier Academic Journal

RAM Memory

Mostafa Youssef, assistant professor of computational materials science and engineering in AUC's Department of Mechanical Engineering, and Mohamed Abdallah '21, a double major in mechanical engineering and physics, have published their research on an innovative technique for making ceramics more durable in the prestigious Physical Review Materials, a top-tier journal in materials science.

Ceramics are used in everyday life – from car parts and building materials to computer chips and cell phone batteries. In his courses at AUC, Youssef and his students explore different materials and their properties using simulations, modeling and theory.

The professor had previously conducted research on a related problem in 2017 during his postdoctoral studies at MIT. “During my time at MIT, we were trying to understand what happens to a piece of ceramic when you expose it to a huge electric field,” he explained.

Prior work found that the air gaps in a piece of ceramic were eliminated  when introduced to large electric fields, making the material denser and more durable. “Usually, people do this with very high temperatures using furnaces in a process called sintering,” Youssef said. “But this is quite expensive. And people are trying to find alternatives that are more cost-efficient.” 

Flash sintering is a promising alternative, as it succeeds in densifying ceramic materials faster and requires less heat than traditional sintering. High electric fields are also used to store information to novel types of Random Access Memory cards for computers that will push the current limits of memory speed.

Ceramics
Applying a large electric field on a ceramic facilitates the motion of its ions. Yellow are negative ions and blue are positive ions.

 

Youssef and Abdallah continued in this area of study in 2019, after they had met the previous year when Abdallah took Youssef’s Numerical Methods course. “During my studies, I grew to appreciate how materials optimization can have a huge influence on the performance of devices or on creating new devices,” Abdallah said. “So maybe seven or eight months after the course, I got in touch with Dr. Mostafa to conduct research as an undergrad in this field.”

The two focused on identifying a model that demonstrated how certain defects in ceramics move when exposed to electrical fields. “We collected previous models from literature starting from the 1940s all the way to 2020,” Youssef explained. “And we made a computer simulation – basically, we brought a little piece of ceramic on the computer, applied an electric field and saw how the defects move.”

There were five models in total, all of which Youssef and Abdallah carefully assessed until they could pinpoint which model was superior. The simulations themselves sometimes took months to finish, and if there were errors in the code that Youssef and Abdallah wrote, they would have to start again.

“One of the things that hit me during this time is that research is an iterative process,” Abdallah said. “It often doesn’t work out right away, so you need to be flexible and adaptable.”

Youssef admired the patience Abdallah demonstrated throughout the process, especially considering his status as an undergraduate student. “Many undergraduate students need to see something coming out immediately, after three or four months,” he said. “But Mohamed was patient. And I think this is a major quality in good research – patience.” 

Other challenges included securing resources for their research and continuing during the coronavirus pandemic. “These simulations need a lot of computational power. And we were very, very limited on the resources,” Youssef explained. “The other thing that was overwhelming for us was COVID. It took us a while to coordinate things and to see how the workflow could run.”

Even after the two finished their paper, they still faced what Youssef described as an “extremely rigorous” review from the academic journal. So rigorous, Youssef recalled, that Physical Review famously critiqued a paper written by Albert Einstein in the 20th century, which prompted the physicist to stop submitting his work to the journal.

Both researchers were elated upon receiving the acceptance email.

“I remember waking up at something like 7am,” Abdallah remembered. "I had class that day, and I was checking my phone before getting ready. I found the email from Dr. Mostafa, and I can say that while we were very confident in our work, receiving the acceptance was a different feeling altogether. It was such a happy day.” 

“We are very proud that we made it [in the journal],” Youssef added. “This is a Q1 journal [Impact 3.99] from the family of the Physical Review series whose papers are permanently cited in Nobel Prize awards in physics and chemistry.”

Q1 journals make up the top 25% of journals in an area of research.

Beyond taking pride in their work, Youssef and Abdallah also hope that their work inspires others, especially undergraduate students, at AUC and beyond to conduct their own research in this field.

“We need such a push for undergraduate research,” Youssef said. “Our undergraduate students are capable of doing high-quality research – it just takes a little bit of patience.”

Abdallah, who is now pursuing a masters at the École polytechnique fédérale de Lausanne (EFPL) in Switzerland, is grateful for the opportunity and guidance provided to him by Youssef. 

“Not only did Dr. Mostafa provide me with technical supervision throughout the project, but his support for my development extended beyond that as well,” he said. “Through his mentorship, I was encouraged to learn and apply skills that are to be demonstrated by a successful scientist and researcher. His support for my academic development also helped me narrow down my academic interests concerning grad school, and make the best use of my background in physics and mechanical engineering. As a result, I was able to join EPFL’s Physics Master of Science program and continue working on atomic scale simulation.”

Youssef continues to lead AUC students in this field, reporting that there are two graduate students currently continuing his and Abdallah’s research. “Mohamed is also passing on what he learned and the tools that he developed to his colleagues here, in order to streamline the process of continuing research,” he said.

Mohamed Abdallah and Mostafa Youssef
Mohamed Abdallah '21 (L) and Professor Mostafa Youssef

 

Finally, Youssef stressed the value of conducting simulations in research. “I feel that sometimes people, even in academia, don't appreciate how powerful it is to simulate something,” he said, adding that while simulations cannot substitute working in a lab, they are cheaper and oftentimes faster.

“If we can convince people through high quality research that you can make something useful via computer simulation (of course, along with experiments), that would be a great achievement,” he said. “It’s what I'm hoping for, ultimately.”

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Main photo courtesy of Possessed Photography on Unsplash