Roy Jyotirmoy, Ravi Teja Pajjuru, Sahu Savita, S Devadarsan, Basheed G A, Gangineni R B
Functional Thin Films Laboratory, Department of Physics, School of Physical, Chemical and Applied Sciences, Pondicherry University, Kalapet, 605014 Puducherry, India.
CSIR-National Physical Laboratory, Dr K S Krishnan Marg, New Delhi 110012, India.
J Phys Condens Matter. 2024 Sep 24;36(50). doi: 10.1088/1361-648X/ad7ac5.
Spin injection across 160 nm thick semi-crystalline Poly(vinylidene fluoride-co-hexafluoropropylene) (PVDF-HFP) is methodically investigated at room temperature in PVDF-HFP/NiFe bilayers and Ag/(NiFe or Co)/PVDF-HFP/NiFe vertical organic spin valves (OSVs) using both the co-planar waveguide ferromagnetic resonance (CPW-FMR: 7-35 GHz) and magnetoresistance (MR) techniques. The structural and microstructural characteristics of PVDF-HFP reveal the formation of mixed non-ferroelectric alpha and ferroelectric beta phases. The spin injection due to the transfer of angular momentum in PVDF-HFP/NiFe is quantified by measuring the spin-mixing conductance () and the enhancement in Gilbert damping () parameters from CPW-FMR data. A significant increase inof 26% andof (2.72 ± 0.45) × 10mhighlights the efficient spin injection into the PVDF-HFP spacer layer. Further, the MR in OSV structures reveals a room temperature spin injection with a maximum MR of 0.278 ± 0.006% for Ag/Co/PVDF-HFP/NiFe and 0.349 ± 0.039% for the Ag/NiFe/PVDF-HFP/NiFe devices. Furthermore, the spin injection processes are discussed w.r.t to bias voltages, interfaces and microwave frequencies.
在室温下，使用共面波导铁磁共振（CPW-FMR：7 - 35 GHz）和磁阻（MR）技术，系统地研究了在聚偏氟乙烯-六氟丙烯（PVDF-HFP）/镍铁双层膜以及银/（镍铁或钴）/PVDF-HFP/镍铁垂直有机自旋阀（OSV）中，自旋注入穿过160纳米厚的半结晶聚偏氟乙烯-六氟丙烯（PVDF-HFP）的情况。PVDF-HFP的结构和微观结构特征显示出混合的非铁电α相和铁电β相的形成。通过测量自旋混合电导（ ）以及从CPW-FMR数据中得出的吉尔伯特阻尼（ ）参数的增强，来量化PVDF-HFP/镍铁中由于角动量转移而产生的自旋注入。 显著增加26%以及 达到(2.72 ± 0.45) × 10 ，突出了向PVDF-HFP间隔层的有效自旋注入。此外，OSV结构中的磁阻显示出室温自旋注入，对于银/钴/PVDF-HFP/镍铁器件，最大磁阻为0.278 ± 0.006%，对于银/镍铁/PVDF-HFP/镍铁器件，最大磁阻为0.349 ± 0.039%。此外，还针对偏置电压、界面和微波频率讨论了自旋注入过程。
