People
Dr. Joseph Heremans
Dr. Heremans' research is focused on thermal transport properties of solids and nanostructures, aimed at developing thermoelectric materials with improved efficiency for both electrical power generation and heat pumping applications. A decade of research in his group and others has led to improved efficiencies through a reduction of the thermal conductivity by adding nanostructrues to thermoelectric materials. In contrast, since 2005, he has focused on developing bulk thermoelectric materials in which the increased efficiency is based on the details of the chemical bonds at sub-nanometer levels. One approach maximizes the anharmonicity of the bonds between atoms to reduce the thermal conductivity, and is published in Phys. Rev. Lett. 101, 035901 (2008). A second approach increases the thermoelectric power by using a resonance between the electronic states of Tl atoms and the valence band of PbTe (Science 321 554, 2008). In 2010, TML reported the first measurement of the spin-Seebeck effect on a semiconductor, in collaboration with Prof. Roberto Myers' group (Nature Materials, 9, 898 (2010)). This effect is a change in spin-polarisation in a temperature gradient. In Phys. Rev. Lett. 106, 186601 (2011) the link was established between the spin-Seebeck effect and the interaction between phonons and "magnons", perturbations of the magnetisation in ferromagnets. These measurements promise to open a new avenue in thermodynamics, called spin-caloritronics: like thermoelectrics converts heat into electricity, spin-caloritronics promises to convert heat into magetism. Click here for more information
Post Docs
Dr. Audrey Chamoire - Post-Doctoral
Audrey received two masters in material sciences and material engineering at the university of Montpellier, France and at Polytech’Montpellier the engineering school of Montpellier in 2006. Her research was focused on the study and the optimization of lead free solder for an electronic card for the world specialist in electric infrastructure Legrand ®. She obtained her Ph.D in 2009 based on the elaboration and the chemical and physical characterization of rare earth antimonides compounds for thermoelectric application at the Institut Charles Gerhardt in Montpellier, France. Then she spent a year as a teaching and research assistant at the University Institute of Technology of Montpellier. She joined the Thermal Nanomaterials Laboratory (TNL) as a popostdoc in Summer 2010 and she is now focus on the optimization of rare earth compounds for thermoelectric application.
Current Students
Chris Jaworski - PhD
Chris received his undergraduate degree in Mechanical Engineering from OSU in Spring 2007. As an undergraduate student, he completed an honors project in the area of thermoelectricity, more specifically Thermoelectric Energy Conversion in Hybrid Vehicles where he designed, constructed, and characterized a benchtop thermoelectric waste heat recovery system. He then joined the Thermal Nanomaterials Laboratory (TNL) and recieved his Masters in Mechanical Engineering in Autumn 2008 with research that focused on lead salts. Currently, he is pursuing his PhD with the the main focus of cooling materials, but has ventured into water splitting materials and new thermomagnetic spintronics phenomena. Click here for more information
Michele Nielsen - PhD
Michele attained her undergraduate degree in Mechanical Engineering at The Ohio State University in Winter 2007. She has been in the TNL since Autumn 2008. She has presented at American Physical Society March Meeting in Pittsburgh, PA in 2009 as well as the Material Research Society Spring Meeting in San Francisco, CA in 2010. Additionally she has attended the IMRS school on oxides at the University of Florida, and presented posters at the Ohio Innovation Summit (2009) and PVIC Spring Meeting (2010). She recently completed her masters work on single phase off-stoichiometric silver antimony telluride. Click for more info.
Hyungyu Jin - PhD
Hyungyu received his Bachelor’s degree in Mechanical Engineering from Korea University, South Korea. After that, he worked as a commissioned research scientist of the Cognitive Robotics Center at Korea Institute of Science and Technology (KIST). He entered MS/PhD combined program in Department of Mechanical Engineering at OSU on September, 2008 and has joined TML since March, 2009. Currently, his main research topic is to develop efficient cryogenic cooling materials, especially focusing on single crystalline bismuth-antimony alloy system. He is also working on polycrystalline bismuth-antimony alloys synthesized by powder metallurgy in order to find mechanically robust, environmentally friendly thermoelectric materials that can be used up to room temperature.
Yibin Gao - PhD
Yibin joined the TNL in September 2009, after graduating with a B.S. in Physics from Peking University, Beijing, China. In his undergraduate research, he constructed a home-made device to measure Seebeck coefficient of multi-walled carbon nanotube bundles. He also worked on thin-film thermocouples. In his senior year, he presented a poster at American Physical Society March Meeting in Pittsburgh, 2009. He gave his first presentation as a graduate student at the Electronic Materials Conference in Notre Dame, IN, 2010. Yibin Gao is currently researching environmentally friendly materials for thermoelectric waste heat recovery.
Eric Evola - PhD
Eric received his B.S. from Missouri S&T with a minor in Spanish before coming to OSU in Autumn 2010. As an undergrad he pursued an interest in automotive engineering at Missouri S&T with groups including the EcoCAR team and Formula Car team. He also focused on merging an interest in Spanish with engineering by working with Engineers without Borders on a water sanitation project in Bolivia and studying in Spain. Upon coming to OSU, he has worked as a graduate teaching assistant for thermodynamics classes and then joined the TNL. He has concentrated on investigating resonant levels in lead chalconides. Click here for more info.
Christine Orovets - Masters
Christine obtained her undergraduate degree in Mechanical Engineering at OSU in Autumn 2010. She completed an undergraduate honors thesis entitled "Design of a Microcombustion-Based Heat Source for Thermoelectric Generation". She joined TNL in January 2011 and is pursuing her masters with a focus on cryogenic materials, specifically dopants in bismuth and bismuth-antimony systems. Click here for more info
Visiting Scholars
Dr. Hiroto Adachi
Hiroto is a visiting scholar at OSU during the summer in 2011. He received his Ph.D from Kyoto University in 2003, and is currently a senior PD fellow at Advanced Science Research Center, Japan Atomic Energy Agency. His current research interest is in the interplay of spin and heat, especially the generation of spin current by heat energy termed "spin-Seebeck effect". For more information, please visit http://asrc.jaea.go.jp/soshiki/gr/mori-gr/adachi/index.html
Dr. Janusz S. Tobola
Janusz is a Professor at the Faculty of Physics and Nuclear Techniques, AGH University of Science and Technology, Krakow 30-059, Al. Mickiewicza 30, Poland. His specialty are ab initio calculations of electronic structures, resistivity and thermopower of semiconductor alloys. He pioneered a new method that is particularly suitable to dilute alloys, which has contributed to advancing the field of theoretical thermoelectrics research. He works in collaboration with the TML laboratory in the context of research on materials for cryogenic temperature Peltier cooling.
Yi Chen - PhD
Materials Science PhD at Zhejang University in China. Yi is at OSU for a one year visit from Autumn 2010-2011.
Recently Graduated
Dr. Vladimir Jovovic
Vladimir recieved his undergraduate degree in Mechanical Engineering at University of Novi Sav. He then selected University of New Hampshire with a focus on computational fluid dynamics and heat transfer for his Masters degree. He then was the founding student of Professor Heremans' group at OSU. Together they pioneered the 'Resonant Level' concept and demonstrated that I-V-VI materials have intrisically low thermal conductivity, making them extremely attractive to thermoelectric researchers. Has published in Science magazine and Physical Review letters on these topics. Vladimir is currently employed in a start-up company zT-Plus in Azusa CA dedicated to the commercialization of materials that were the focus of his dissertation.
