• 文献标题:   Toward Nonvolatile Spin-Orbit Devices: Deposition of Ferroelectric Hafnia on Monolayer Graphene/Co/HM Stacks
  • 文献类型:   Article
  • 作  者:   LANCASTER S, ARNAY I, GUERRERO R, GUDIN A, GUEDEJAMARRON A, DIEZ JM, GARTNER J, ANADON A, VARELA M, CAMARERO J, MIKOLAJICK T, PERNA P, SLESAZECK S
  • 作者关键词:   spinorbit device, nonvolatile device, ferroelectric hafnia, atomic layer deposition, perpendicular magnetic anisotropy
  • 出版物名称:   ACS APPLIED MATERIALS INTERFACES
  • ISSN:   1944-8244 EI 1944-8252
  • 通讯作者地址:  
  • 被引频次:   0
  • DOI:   10.1021/acsami.2c22205 EA MAR 2023
  • 出版年:   2023

▎ 摘  要

While technologically challenging, the integration of ferroelectric thin films with graphene spintronics potentially allows the realization of highly efficient, electrically tunable, nonvolatile memories through control of the interfacial spin-orbit driven interaction occurring at graphene/Co interfaces deposited on heavy metal supports. Here, the integration of ferroelectric Hf0.5Zr0.5O2 on graphene/Co/heavy metal epitaxial stacks is investigated via the implementation of several nucleation methods in atomic layer deposition. By employing in situ Al2O3 as a nucleation layer sandwiched between Hf0.5Zr0.5O2 and graphene, the Hf0.5Zr0.5O2 demonstrates a remanent polarization (2Pr) of 19.2 mu C/cm2. Using an ex situ, naturally oxidized sputtered Ta layer for nucleation, we could control 2Pr via the interlayer thickness, reaching maximum values of 28 mu C/cm2 with low coercive fields. Magnetic hysteresis measurements taken before and after atomic layer deposition show strong perpendicular magnetic anisotropy, with minimal deviations in the magnetization reversal pathways due to the Hf0.5Zr0.5O2 deposition process, thus pointing to a good preservation of the magnetic stack including single-layer graphene. X-ray diffraction measurements further confirm that the high quality interfaces demonstrated in the stack remain unperturbed by the ferroelectric deposition and anneal. The proposed graphenebased ferroelectric/magnetic structures offer the strong advantages of ferroelectricity and ferromagnetism at room temperature, enabling the development of novel magneto-electric and nonvolatile in-memory spin-orbit logic architectures with low power switching.