Caloric Effects in Magnetic Materials
INRIM, Sala Conferenze
University of South Florida
Tampa, Florida, USA
Caloric effects in magnetic materials have generated a lot of interest in the scientific community over the years owing to their impact on technological applications such as refrigeration, waste heat recovery for power generation, thermoelectric and spintronic devices.
There are many caloric effects generally related to the coupling of ferroic order parameters to external magnetic fields and phase transitions or generation and manipulation of pure spin currents through thermal gradients.
In this talk we would focus on two such caloric effects namely the magnetocaloric effect (MCE) and spin caloric effect (SCE) and present recent advances on these topics made in our Functional Materials Laboratory.
We demonstrate that it is possible to combine thermoelectric and magnetocaloric properties for dual functional refrigeration in Eu8Ga16Ge30 semiconducting clathrates. By forming composites with EuO we can tune the optimal MCE characteristics, operating temperature range and refrigerant capacity. In the other area of spin caloritronics, we emphasize the important role of magnetic anisotropy and interface coupling between the magnetic insulator (YIG) and metal (Pt) layers through systematic investigations of the anisotropy and spin Seebeck effect (SSE).
We discuss the exciting possibility of improving the spin mixing conductance and enhancing SSE through appropriate choice of buffer layers between YIG and Pt.
Overall, we will present an overview based on our research how these caloric effects can lead to new and improved thermomagnetic devices.
Hari Srikanth is a professor of physics at the University of South Florida (USF).
He received the Ph.D. in experimental condensed matter physics from the Indian Institute of Science.
After postdoctoral research for several years, he joined USF in 2000, where he established the Functional Materials Laboratory.
His research spans a wide range of topics including magnetic nanoparticles, magnetic refrigerant materials, spin calorics, and complex oxides.
He has published about 250 journal articles and given numerous invited talks.
Dr. Srikanth is a Fellow of the American Physical Society and a Senior Member of IEEE. He is an associate editor of the Journal of Applied Physics.
He has been closely involved with the Magnetism and Magnetic Materials and INTERMAG conferences for more than 15 years, serving as editor, publications chair, and as a member of program committees.