Chemistry

Home » Archives for 2024 » Page 2

Archives for 2024

New Graduate Student Fellowship Awarded

by

Graduate student fellowships are financial gifts that provide support for graduate students and their research. These gifts can make it possible for students to give presentations at national conferences, purchase materials for lab work, and more. In 2024, the Department of Chemistry awarded a new graduate student endowed fellowship, thanks to the generosity of Robert and Phyllis Yokley.

Robert Yokley is an alumnus of the University of Tennessee Knoxville’s Department of Chemistry. Born in Hohenwald, Tennessee, Yokley began studying chemistry at Middle Tennessee State University. That study was interrupted by the Vietnam War, where he served a tour of duty as a U.S. Marine. When he returned home, Yokley returned to his studies and completed his B.S. degree. After working as a chemist for the Tennessee Department of Agriculture, Yokley decided to continue his education and joined the Department of Chemistry at UT, where he worked under Professor Gleb Mamantov.

After receiving his PhD, Yokley went on to work as a chemist in industry until his retirement in 2006. Yokley remains an active member of the American Chemical Society where he has served as the Chair of the Senior Chemists Committee.

The Dr. Robert A. and Phyllis F.J. Yokley Endowed Fellowship is the result of Yokley’s hard work over the years, and desire to support new generations of upcoming chemists. In keeping with Yokley’s experience, the fellowship gives preference to veterans, specifically members of the Marine Corps. The first recipient of the fellowship was graduate student and Marine Corps veteran Dakota Landrie.

A South Caroline native, Landrie joined the Marines right after high school, citing a desire to challenge himself. During his service, he deployed to Afghanistan twice with the 3rd Battalion, 7th Marine Regiment.

Landrie joined the chemistry graduate program in Fall 2022 and is now a member of Associate Professor Sharani Roy’s research group. His research uses theoretical models to explore electron transport. Currently in his third year, Landrie is working to become an interdisciplinary scientist, focusing on chemical physics.

“I am honored to receive this award and would like to thank Dr. Yokley for his service,” said Landrie.

The Dr. Robert A. and Phyllis F.J. Yokley Endowed Fellowship was awarded for the very first time at the department’s 2024 Honors Day, an event that celebrates the achievements of faculty, staff, and students. Robert and Phyllis Yokley were in attendance, along with their dog Otis.

Graduate Student Brings STEM Education to Knoxville Youth

by

Candace Halbert, PhD candidate in the Department of Chemistry, was recognized by People Magazine last year for her work bringing STEM education to underserved Knoxville youth through her nonprofit organization Youth Outreach in STEM (YO-STEM). As a nontraditional student, Halbert is building the skills and knowledge that will allow her to serve her community and benefit the life and lives of children all over Knoxville.

After earning her master’s degree from Georgia Tech, Halbert pursued a career as a chemist and eventually began working as a scientific associate at the Spallation Neutron Source at Oak Ridge National Laboratory (ORNL). Halbert’s role at ORNL quickly expanded beyond managing a research instrument to include recruiting at conferences and career fairs.

As she continued working as a STEM professional, Halbert noticed that she was often the only woman or person of color in the room. She found herself wondering what could be done to change that. In 2016, in the wake of the ongoing water crisis in Flint, Michigan, Halbert stopped wondering and started acting.

“Vine Middle School was collecting water for Flint so I went to donate, and I realized Vine was a STEAM school. I offered to volunteer and a few weeks later they contacted me and asked if I would be interested in starting a STEM program for girls,” said Halbert.

What began as a STEM club for girls, quickly expanded to a co-ed Build-a-Drone program, and in 2017, Halbert founded YO-STEM. YO-STEM is a nonprofit dedicated to providing underserved students with education and hands-on STEM experiences. Its three main programs are the original Girls in STEM program, STEM Saturday, and competitive co-ed Robotics. The first year YO-STEM’s robotics team competed, the made it all the way to the VEX Robotics World Championship.

“Our kids are amazing. All they need is the resources, time, and energy to be devoted to them,” said Halbert. “I always tell people we’re not saving these kids. We are giving them a tool and they’re learning to do everything they need with it. They’re strategizing, they’re practicing, they’re communicating. They’re doing the work; we’re just supplying the opportunity.”

Halbert’s journey to the Department of Chemistry at UT is intimately tied to her work with YO-STEM. Her experience as a working scientist in a national lab led Halbert to believe that a PhD would open new doors for her professionally, but she was hesitant to add graduate school to her existing priorities. As Halbert continued pouring energy into her nonprofit, YO-STEM expanded its services to more students and age brackets. It wasn’t long before one of her colleagues suggested she return to graduate school.

“I was speaking to my mentor and she pointed out how much more I could do for my community with a PhD. All this time friends and colleagues had said I should go back to school because it would help my career, and I knew they were right,” said Halbert. “But my mentor reminded me this degree could do so much more than just help my career, that it could really enable me to better serve my community and these students.”

After joining the PhD program at UT, Halbert quickly realized how different this graduate school experience would be. Some of this she attributed to her professional experience and personal growth, both natural and intentional. However, she also found the program’s focus on research and fostering rigorous scientific inquiry to be a much more effective approach for her as a student.

“This has been a completely different experience for me.  As part of an R-1 institution, the structure of the program here focuses on high-quality research and research proposals as measurements of success and ability,” said Halbert. “I think that’s a better way to prepare students for their future careers. The department is also very supportive. I can tell my committee wants me to succeed.”

Now in her third year, Halbert feels confident that she made the right choice to pursue a PhD at UT. She says that balancing her work as a graduate student, her work at ORNL, and her work with YO-STEM has been challenging but rewarding. In the last few years, she has welcomed other members of the chemistry program into the family of volunteers at YO-STEM, and is considering further expanding the organization’s offerings as students ask for additional programs. Halbert has even begun to see some of the earliest participants in her programs joining the Volunteer family as undergraduate students.

 One of my students is in computer science and another is in nursing. I love seeing them here at UT. It’s almost like we’ve come full circle,” said Halbert

As Halbert continues to progress through her PhD program, she is looking forward to leveraging the knowledge and skills she has gained at UT to the benefit of both her career and community. She has discovered her passion in STEM advocacy and says the Department of Chemistry has provided her with the invaluable education and experience she needs to become an even stronger advocate.

Learn more about YO-STEM here.

Photo of a poster session

2024 Honors Day

by

On Thursday, May 2nd the Department of Chemistry held its annual Honors Day event. Honors Day is an opportunity to recognize student, faculty, and staff excellence via awards and fellowships. This year the Dr. Robert A. and Phyllis F.J. Yokley Endowed Fellowship was awarded for the first time. Dr. and Mrs. Yokley traveled from their home in North Carolina to join the celebration and meet the first winner of their fellowship. Distinguished alumnus Dr. Subu Natesan, CEO and President of AstraGlass Innovations, delivered the opening address.

Honors Day Awardees

Outstanding PhD Candidate Awards

Shahzad Akram (not pictured)
Bukola Ogunyemi

Outstanding Graduate Teaching Awards

Lydia Lang
Vernon Stafford

Charles W. Keenan Award

Zack Hulsey

Three people pose for a photo at an awards ceremony with a UT backdrop behind them
Four people pose for a photo at an awards ceremony with a UT backdrop behind them
Three people pose for a photo at an awards ceremony with a UT backdrop behind them

Jerome Eastham Fellowship in Organic Chemistry

Dillon McBee

Graduate Fellowship for Achievement in Inorganic Chemistry

Adam Hand

Judson Hall Robertson Graduate Award in Analytical Chemistry

Kevin Siniard

Three people pose for a photo at an awards ceremony with a UT backdrop behind them
Three people pose for a photo at an awards ceremony with a UT backdrop behind them
Three people pose for a photo at an awards ceremony with a UT backdrop behind them

Eugene John Barber Fellowship in Physical Chemistry

Jeffrey Laub

Dr. Robert A. & Phyllis F.J. Yokley Endowed Fellowship

Dakota Landrie

Gleb Mamantov Graduate Chemistry Scholar

Miranda Limbach

Three people pose for a photo at an awards ceremony with a UT backdrop behind them
Five people pose for a photo at an awards ceremony with a UT backdrop behind them
Three people pose for a photo at an awards ceremony with a UT backdrop behind them

ACGS Awards

ACGS Member of the Year

Brandon Sanders
Amarachi Sylvanus
Christy Witcher (not pictured)

James F. Green ACGS Service Award

Crystal Armstrong
Jennifer Brown

Four people pose for a photo at an awards ceremony with a UT backdrop behind them
Four people pose for a photo at an awards ceremony with a UT backdrop behind them

Carol Moulton ACGS Service Award

Linda Sherman (not pictured)

Staff Awards

Outstanding Service Awards

Eric Mercer
Matt Tomm

Two people pose for a photo at an awards ceremony with a UT backdrop behind them
Two people pose for a photo at an awards ceremony with a UT backdrop behind them

Faculty Awards

Zeigler Professorship

Mark Dadmun (not pictured)

Slide on a screen showing Chemistry Honors Day
People eating and talking at the event
People eating and talking at the event
A man speaking with a photo of the Torchbearer statue behind him
A man talking behind a table
A thank you slideshow
Someone holding a small dog on their lap
Men shaking hands
A woman holding an orange UT tote bag
Photo of a poster session

2024 Undergraduate Awards

by

On Saturday, April 27th the 3rd annual Undergraduate Research Symposium took place in Mossman Hall, with undergraduate students participating in poster and oral presentation competitions. Following the symposium, chemistry undergraduates, family and friends attended the accompanying awards dinner where symposium awards and undergraduate scholarships were distributed. Congratulations to all of this year’s winners!

Undergraduate Research Symposium Award Winners

Poster Award Winner

Maryam Ahmed

Poster Award Winner

Grayson Cobb

Oral Presentation Winner

Kendra Day

Oral Presentation Winner

Makayla Hedges

Scholarship Award Winners

C.W. Keenan Outstanding General Chemistry Student Award

Vu (Lynn) Nguyen

Phillip & Mary Reitano Award

Rahil Parikh

Dr. Lucy E. Scroggie Scholarship

Caleb Russell

Halbert and Anne Carmichael Scholarship

Bailey Dvorak

C.A. Buehler Chemistry Scholarship

Makayla Hedges

Additional Awards (not pictured)

ACS-Hach Land Grant Scholarship

Nathan Stimpson

CRC Press General Chemistry Award

Reed Heflin

Melaven-Rhenium Scholarships

Bailey Dvorak
Chloe Earls
Alexandria Wood

Chemistry Professor Emeritus Michael J. Sepaniak Passes Away

by

It is with great sadness that we commemorate the passing of Michael J. Sepaniak, professor emeritus of chemistry. Sepaniak joined the Department of Chemistry at the University of Tennessee, Knoxville in 1981, where he spent nearly 40 years conducting research, teaching, and mentoring graduate students.

During his time at UT, Sepaniak investigated microfluidics, optical spectroscopy, and chemical sensing. He was a Paul and Wilma Ziegler Professor of Chemistry and served as department head from 1995 through 2003. Sepaniak retired in 2018, but maintained a post-retirement position with the department until 2020.

He will be greatly missed. The Department of Chemistry is grateful for his service and time at the university.

Hatab Honored with Lorayne Lester Award

by

Nahla Hatab is presented with the Lester Award by Robert Hinde at the Faculty Awards Ceremony

During the 2023 UT College of Arts and Sciences faculty convocation, Nahla Abu Hatab, senior lecturer and director of general chemistry, received the Lorayne W. Lester Award, which recognizes a faculty member or an exempt staff member who has demonstrated outstanding service through research, outreach, and/or administrative, teaching, or advising services to the UT College of Arts and Sciences, State of Tennessee, local community, or beyond. 

Hatab is a champion of chemistry and recognized tonight for her support of high-quality teaching in our general chemistry courses. She continuously demonstrates excellence in teaching large, lower-level division chemistry classes, which can be a real challenge! 

As a lab program director, she supports lab safety and first-year chemistry labs in general, and contributed to the new curriculum of the first-year chemistry labs. Not only does she serve our college and help students achieve success in their first years of chemistry, she works with colleagues in the education college to study the pedagogical techniques in our first-year chemistry labs and lectures for continuous improvement. 

Ferroelectric-Hafnia-Singh

Musfeldt Leverages Pressure for Future Energy Storage

by

A group of researchers including Jan Musfeldt, Ziegler professor of chemistry at the University of Tennessee, recently published in the Proceedings of the National Academy of Sciences (PNAS). The article details the discovery that pressure can be used to create and control the phase and properties of hafnia.

Hafnium oxide, or hafnia, is a material that has interested researchers for many decades. Highly insoluble and temperature stable, hafnia has been leveraged in applications as diverse as optical coatings for glasses and camera lenses, fuel cells, and passive building insulation. Advanced electronics and energy storage applications are, however, generating the most excitement.

Since 2007, amorphous hafnia thin films have been employed as gate dielectrics in CMOS technology, enabling the continuation of Moore’s scaling of DRAM chips. Ferroelectricity and silicon compatibility make hafnia an attractive candidate for nonvolatile ferroelectric FET devices as well as negative capacitance heterostructures. Recent break-throughs impacting the development of advanced chip technologies include the discovery of flat phonon bands and their connection to the energy landscape in the vicinity of the polar phase and the incredibly rich variety of competing phases in crystalline thin films of hafnia.

“I love this project!” said Musfeldt. “It brings together the fundamental science of phase competition under external stimuli and work at the Frontier Infrared Spectroscopy beamline at the National Synchrotron Light Source II with the growth of whole families of high-quality single crystals and complementary first-principles theory to predict phase stability, signatures, and properties. It’s also a great chance to work with friends from Rutgers, Rochester, and Brookhaven.”

One challenge in this field involves the use of very high temperature laser floating zone and rapid quenching process of the crystal growth combined with an yttrium stabilizer in concentrations of up to 20%. While effective, the high levels of yttrium used impacts the purity of the material, which in turn affects performance.

Musfeldt and her collaborators wanted to investigate an alternative means of creating the various phases of hafnia using less stabilizer. They settled on compression (or pressure) as a technique with the potential to do the job. The fact that pressure changes bond lengths and angles provides access to exciting new and stable phases of materials. A similar approach was used in the development of synthetic diamonds.

Hafnia crystal photographed by Jan Musfeldt.

Musfeldt’s team, including post-doctoral researcher Yanhong Gu, conducted a series of experiments using pressure to coax hafnia into the desired antiferroelectric phase. They found that not only did this method work, but the material also remained stable once pressure was removed. Repeated analysis of the product led them to conclude that the material was indefinitely stable at room temperature.

“The material remains stable both with time and through high-temperature annealing,” said Gu.

In addition to showing that compression was a suitable means of achieving a stable antiferroelectric state in hafnia, Musfeldt’s team also confirmed this “pressure-induced chemical reaction” could be done at room temperature with 36% less yttrium stabilizer than previously required by high temperature growth techniques.

“Reducing the among of yttrium stabilizer is crucial to preserving the fundamental performance of these materials”, says Musfeldt.

At the same time, the team was able to use even higher pressures to create the tetragonal form of hafnia. This phase had been theoretically predicted to exist but never confirmed until now.

To identify these previously elusive phases, Musfeldt’s team used predictions developed by her collaborators at the University of Rochester and Rutgers University. Sobhit Singh, David Vanderbilt, and Karin Rabe specialize in computationally predicting the properties of materials. They calculated that compression could be used to stabilize both the antiferroelectric and tetragonal forms of hafnia as well as the vibrational fingerprints that were matched with the experimental measurements.

This figure from the publication summarizes the pressure pathways and various phases of hafnia, including the theorized tetragonal phase, confirmed by Musfeldt.

“Our first-principles calculations unambiguously predict the phase transition from the mixed-phase structure to the desired pure-metastable phase of hafnia at pressures above 6 GPa,” said Sobhit Singh, co-author and assistant professor at the University of Rochester.

“It’s exciting when theory and experiment dovetail so beautifully”, says Musfeldt.

PNAS is one of the world’s most-cited and comprehensive multidisciplinary journals. The full article can be found here. 

Feature image courtesy of Sobhit Singh, University of Rochester.