Abstract. The development of next-generation computing devices based on spintronics and magnonics requires an
understanding of how magnetic spin textures can be tailored in patterned magnetic materials. Within the wide range
of magnetic materials available, complex oxides such as ferromagnetic (FM) La0.7Sr0.3MnO3 (LSMO) and
antiferromagnetic (AF) La1-xSrxFeO3 (LSFO) provide an ideal platform for tailoring magnetic spin textures when
lithographically patterned as nano/micromagnets. This unique tunability arises due to the strong interactions
between charge, spin, lattice, and orbital degrees of freedom. In this talk I will demonstrate how an intricate
interplay exists between shape and magnetocrystalline anisotropy energies as well as exchange coupling
interactions at LSMO/LSFO interfaces, and therefore, the resulting AF and FM spin textures can be controlled using
parameters such as the LSMO and LSFO layer thicknesses, micromagnet shape, and temperature.[1] These spin
textures are imaged using x-ray photoemission electron microscopy for a variety of shapes (circles, squares,
triangles, and hexagons with their edges oriented along different low index crystallographic directions) with and
without their core regions removed (aka donut structures). LSMO nanomagnets were also patterned into artificial
spin ice (ASI) structures,[2] where large arrays of nanomagnets are arranged into geometries where all the magnetic
interactions cannot be satisfied simultaneously. While one might expect shape anisotropy to dictate Ising states in
the nanomagnets, the unique combination of magnetic parameters associated with LSMO enables the formation of
both Ising and complex spin textures (CSTs) based on the nanoisland width and spacing. These CSTs consist of
single and double vortices and alter the nature of dipolar coupling between nanomagnets, giving rise to exotic
physics in the ASI lattices. These studies demonstrate that complex oxide provide a unique platform for engineering
FM and AF spin textures for next generation spin-based devices.

Biography:

Biography. Yayoi Takamura received her B.S. from Cornell University in 1998 and her M.S. and Ph.D. degrees
from Stanford University in 2000 and 2004, respectively, all in the field of Materials Science and Engineering. She
was a postdoctoral researcher at UC Berkeley with Prof. Yuri Suzuki in the Dept. of Materials Science and
Engineering before joining the Dept. of Materials Science and Engineering at UC Davis in July 2006. Since July
2020, she has been serving as Department Chair. Her research focuses on the growth of complex oxide thin films,
heterostructures, and nanostructures and the characterization of the novel functional properties associated with their
interfaces and as they are confined to micro/nanoscale dimensions. Prof. Takamura is a recipient of the NSF
CAREER Award, the DARPA Young Faculty Award, the 2020 UC Davis College of Engineering Mid-Career
Research Award, and an IEEE Magnetics Society Distinguished Lecturer for 2025-2027.