Presentation Information
[11p-E214-7]B-Site Engineering of La--BiFeO3 Thin Films: Correlating Magnetic and Insulating Properties for Memory Devices
〇(DC)Swati Sucharita Das1, Genta Egawa1, Satoru Yoshimura1 (1.Akita Univ.)
Keywords:
Multiferroic material,Thin films,Magnetic and Insulating Properties
Multiferroic Bismuth Ferrite (BiFeO3, BFO) is a promising candidate for low-power magnetic memory devices due to its room-temperature electric-field-driven magnetization switching. However, its low saturation magnetization (Ms), weak perpendicular magnetic anisotropy (PMA), and poor insulating properties limit its application in racetrack memory. To address these issues, La-substituted BFO thin films with B-site substitution (Mn, Co, Ni, Cu) up to 40 at.% and Ni+Co co-substitution were investigated. Ta/Pt/(Bi,La)(Fe,M)O3 thin films were deposited on SiO2/Si substrates using reactive pulsed-DC sputtering with VHF plasma assistance. Co substitution produced the highest Ms, while Ni enhanced PMA. Co-substituted films retained superior insulating properties, whereas high Ni content increased leakage current due to oxygen-vacancy-related defects. XPS revealed that magnetic and electrical properties are strongly influenced by electronic-state modifications and oxygen vacancies. Ni+Co co-substitution yielded synergistic improvements, combining high Ms and enhanced PMA. Optimized 1:1 Ni:Co films exhibited the best balance between magnetic performance and insulation, demonstrating the effectiveness of B-site engineering for BFO-based next-generation magnetic memory applications.