Accelerated Screening of Magnetocalorics:
How Data, Synthesis, Computation, and Measurement Come Together

Developing “rational” design rules for advancing functional materials is an important goal in materials chemistry research. I will describe an effort to seek out exciting new room-temperature magnetocaloric materials –– materials that can cool upon cycling through a magnetic field. The material property of interest in finding candidate magnetocaloric materials is their gravimetric entropy change upon application of a magnetic field under isothermal conditions. We have proposed a simple computational proxy based on carrying out density functional theory calculations on magnetic materials. The proxy –– which we refer to as the magnetic deformation ΣM –– is a measure of how much the unit cell deforms when comparing the relaxed structures with and without the inclusion of spin polarization. ΣM appears to correlate very well with experimentally measured magnetic entropy change values.[1] I will also describe efforts to speed up the preparation of these materials, and to measure their properties more rapidly.

Ram Seshadri is the Fred and Linda R. Wudl Professor of Materials Science at UC Santa Barbara, in the Materials Department and the Department of Chemistry and Biochemistry. He received his PhD in Solid State Chemistry in 1995 from the Indian Institute of Science, Bangalore, and after some years as a postdoctoral fellow in Europe, returned to Bangalore as an Assistant Professor in 1999. He moved to UC Santa Barbara in 2002. At UCSB, he also serves as the Director of the Materials Research Laboratory: A National Science Foundation Materials Research Science and Engineering Center (NSF-MRSEC). His research, embodied in 300+ publications, addresses the topic of structure-property relations in crystalline inorganic materials, with a focus on materials for energy applications. He is a Fellow of the Royal Society of Chemistry, the American Physical Society, and the American Association for the Advancement of Science. He serves as the Associate Editor of Annual Reviews of Materials Research (on the Committee since 2008), and as an Associate Editor of Chemistry of Materials (since 2015).

[1] J. D. Bocarsly, E. E. Levin, C. A. C. Garcia, K. Schwennicke, S. D. Wilson, and R. Seshadri, A simple computational proxy for screening magnetocaloric compounds, Chem. Mater. 29 (2017) 1613–1622.