Moorsom T, Rogers M, Scivetti I, Bandaru S, Teobaldi G, Valvidares M, Flokstra M, Lee S, Stewart R, Prokscha T, Gargiani P, Alosaimi N, Stefanou G, Ali M, Al Ma'Mari F, Burnell G, Hickey B J, Cespedes O
School of Physics and Astronomy, University of Leeds, Leeds LS2 9JT, UK.
Stephenson Institute for Renewable Energy, Department of Chemistry, University of Liverpool, Liverpool L69 3BX, England.
Sci Adv. 2020 Mar 20;6(12):eaax1085. doi: 10.1126/sciadv.aax1085. eCollection 2020 Mar.
We show that hybrid MnO/C heterojunctions can be used to design a storage device for spin-polarized charge: a spin capacitor. Hybridization at the carbon-metal oxide interface leads to spin-polarized charge trapping after an applied voltage or photocurrent. Strong electronic structure changes, including a 1-eV energy shift and spin polarization in the C lowest unoccupied molecular orbital, are then revealed by x-ray absorption spectroscopy, in agreement with density functional theory simulations. Muon spin spectroscopy measurements give further independent evidence of local spin ordering and magnetic moments optically/electronically stored at the heterojunctions. These spin-polarized states dissipate when shorting the electrodes. The spin storage decay time is controlled by magnetic ordering at the interface, leading to coherence times of seconds to hours even at room temperature.
我们表明，混合MnO/C异质结可用于设计一种自旋极化电荷存储器件：自旋电容器。碳-金属氧化物界面处的杂化作用会在施加电压或光电流后导致自旋极化电荷俘获。X射线吸收光谱揭示了强烈的电子结构变化，包括1电子伏特的能量位移和碳最低未占据分子轨道中的自旋极化，这与密度泛函理论模拟结果一致。μ子自旋光谱测量进一步独立证明了在异质结处光学/电子存储的局部自旋有序和磁矩。当电极短路时，这些自旋极化状态会消散。自旋存储衰减时间由界面处的磁有序控制，即使在室温下也能实现数秒至数小时的相干时间。
