Prof. Xiaojia Wang of Department of Mechanical Engineering, University of Minnesota, Twin Cities

In this talk, I will highlight our group activities in engineering thermal transport and magnetization dynamics in functional materials for applications including thermal regulation and energy-efficient spintronics. Such activities are enabled by utilizing the ultrafast laser-based metrology operated in the basic time-domain thermoreflectance (TDTR) and advanced time-resolved magneto-optical Kerr effect (TR-MOKE) configurations. The first example is the solid-state control of thermal transport in nanoscale lanthanum strontium cobaltite (LSCO), where we demonstrate the continuous tuning of LSCO thermal conductivity by a factor of over five. This tuning is achieved via a room-temperature electrolyte-gate-induced non-volatile topotactic phase transformation from perovskite to an oxygen-vacancy-ordered brownmillerite phase, accompanied by a metal-insulator transition. The second sample system is L1₀-FePd, as a promising candidate for energy-efficient and non-volatile spintronic devices with large areal densities. We systematically examine the impacts of buffer-layer engineering on the perpendicular magnetic anisotropy (related to the switching speed) and Gilbert damping (related to the energy consumption) to better address the technological viability of L1₀-FePd for spintronic applications. Lastly, I will share our group’s efforts in exploring the rich physics of magnetization dynamics in complex architectures, including Co/Pd multilayers and perpendicular synthetic antiferromagnets, both of which are crucial for developing next-generation spintronic devices with fast and energy-efficient switching.

References:

[1] Zhang et al, Nature Communications, 14, 2626 (2023).

[2] Huang et al., Physical Review B, 107 (21), 214438 (2023).

[3] Lyu et al., Advanced Functional Materials, 33, 2214201 (2023).

[4] Huang et al., Physical Review Materials, 6, 113402 (2022).

[5] Zhang et al., Science Advances, 6(38), eabb4607 (2020).

[6] Wu et al., Advanced Functional Materials, 27(47), 1704233 (2017).

Biography:

Xiaojia Wang is currently an associate professor in the Department of Mechanical Engineering at the University of Minnesota, Twin Cities. Prior to this, she was a postdoctoral research associate in the Department of Materials Science and Engineering at the University of Illinois at Urbana Champaign. She received her Ph.D. in Mechanical Engineering from the Georgia Institute of Technology in 2011, and her M.S. in 2007 and B.S. in 2004 from Xi'an Jiaotong University, China, all in Mechanical Engineering. For details, please visit her research group website: https://mnttl.umn.edu/publications

Address:Department of Mechanical Engineering, University of Minnesota, Twin Cities, Minneapolis, Minnesota, United States, 55455