Apr 02, 2019 3:45 pm - Nielsen Hall 170 - Colloquium
Shalinee Chikara - Auburn University
Magnetoelectric behavior via a spin state transition

Magnetoelectrics are a heavily-investigated class of materials where magnetic and dielectric/ferroelectric properties couple to each other in an insulator. These materials offer the potential for lower power consumption for electronic devices such as sensors, memories and transducers since they sense and control magnetic states using electric voltages instead of electric currents. My talk focuses on a different approach to magnetoelectric coupling in which we control the electric polarization with a magnetic spin state transition instead of the traditional ferro- or antiferromagnetic order. We demonstrate that a first-order magnetic field-induced spin state transition from the S = 1 to S = 2 state of a molecular Mn3+ compound induces a structural phase transition with a large change in electric polarization. This material is one member of a growing class of compounds numbering in hundreds of thousands where the spin state transition can modify the structure and provide a yet unexplored direction to seek magnetoelectric coupling by triggering transformations between structures with different electrical properties. The research was performed with collaborators at Los Alamos National Laboratory (N. Smythe, J. Singleton, B. Scott, Vivien S. Zapf), University of Florida (J. Gu, X.-G. Zhang, H.-P. Cheng), and Harvey Mudd College (E. Krenkel, J. Eckert).