Interfacial effects on the microstructures and magnetoresistance of Ni80Fe20/P3HT/Fe organic spin valves

• Published in: Journal of alloys and compounds Vol. 769; pp. 991 - 997
• Main Authors: He, Jie, Zheng, Lingcheng, Feng, Deqiang, Liu, Mengyin, Shao, Dawei, Lu, Zunming, Zhang, Xinghua, Wang, Weihua, Wang, Weichao, Lu, Feng, Dong, Hong, Cheng, Yahui, Liu, Hui, Zheng, Rongkun
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 15.11.2018
• Subjects: Anisotropic magnetoresistance; Inverse spin-valve effect; Organic spin valves; P3HT; Organic spin valves; Inverse spin-valve effect; Anisotropic magnetoresistance; P3HT
• ISSN: 0925-8388; 1873-4669
• DOI: 10.1016/j.jallcom.2018.08.024

A series of Ni80Fe20/poly(3-hexylthiohene) (P3HT)/Fe organic spin valves (OSVs) have been prepared by ion beam assisted deposition combined with spin coating technique. A negative magnetoresistance (MR) with the value of 0.08% at room temperature is observed, exhibiting an inverse spin-valve effect, indicating that the MR behavior in Ni80Fe20/P3HT/Fe spin valve is distinctive and different from that in the Co-based P3HT spin valves. After increasing the bombarding energy of the top electrode, an additional positive MR is observed at low magnetic field range. By comparing with the MR under different relative direction of electric current and magnetic field in P3HT/Fe bilayers, the positive MR observed in OSVs is attributed to the anisotropic magnetoresistance (AMR) of the Fe/P3HT interfacial layer. These experimental results demonstrate that the interfacial layer plays an important role in the MR behavior of OSVs. On one hand, the interfacial layer adjusts the electronic structure to induce the inverse spin-valve effect; on the other hand, it affects the magnitude of MR. These results can help us understand the role of the interactions between organic semiconductors and metal electrodes in the organic spintronic systems. •An inverse spin-valve effect in Ni80Fe20/P3HT/Fe spin valve was observed.•The value of MR of Ni80Fe20/P3HT/Fe spin valve is around 0.08% at the room temperature.•Two types of MR were observed after increasing the Fe deposition energy.•The positive MR in spin valve can be attributed to AMR of Fe/P3HT interlayer.