TY - JOUR
T1 - Room temperature magnetoresistance effects in ferroelectric poly(vinylidene fluoride) spin valves
AU - Zhang, Xianmin
AU - Tong, Junwei
AU - Zhu, Huie
AU - Wang, Zhongchang
AU - Zhou, Lianqun
AU - Wang, Shouguo
AU - Miyashita, Tokuji
AU - Mitsuishi, Masaya
AU - Qin, Gaowu
N1 - Funding Information:
This work was supported by the National Natural Science Foundation of China (No. 51471046, 51525101, 51431009, 51625101), the Project of Key Laboratory of Liaoning Provincial Education Department (No. LZ2015039), and the Research Funds for the Central Universities (N151004002, N160208001). H. Z. and M. M. are grateful for the financial support from Grants-in-Aid for Young Scientists (B) (16K17953), Scientific Research (B) (16H04197) from JSPS, Innovative Areas (15H00719) and the Cooperative Research Program "Network Joint Research Center for Materials and Devices" from MEXT in Japan.
Publisher Copyright:
© 2017 The Royal Society of Chemistry.
PY - 2017
Y1 - 2017
N2 - Ferroelectric poly(vinylidene fluoride) (PVDF) nanofilms have been fabricated by the Langmuir-Blodgett technique, possessing mainly a ferroelectric active phase and a controllable film thickness of 2.3 nm per layer. Atomic force microscopy and Fourier transform infrared spectroscopy were utilized to characterize the film properties. Importantly, the PVDF films could act as barrier layers to prepare spin transport devices using Fe3O4 and Co as bottom and top ferromagnetic electrodes, respectively. Spin-dependent electron transport behaviors were systemically studied in these devices by varying the PVDF film thickness from 3 layers (7 nm) to 13 layers (30 nm). With increasing PVDF layer numbers, the magnetoresistance (MR) response decreases likely due to the change in spin transport from tunneling to hopping transport. We further investigated the MR dependence on operation temperatures (150 K, 200 K, 250 K and 300 K). It is noteworthy that the MR effect was observed even at 300 K with an MR ratio exceeding 2.5%, which is achieved for the first time in such organic devices. The device performance could be further improved at lower operation temperatures. The MR ratios, device resistances and electron transport mechanisms in the present devices were also discussed to analyze the spin transport behaviors. The results indicate that the ferroelectric PVDF nanofilms are promising candidates for spin devices operated at room temperature, thereby shedding light on the design of organic ferroelectric spintronics with a higher performance.
AB - Ferroelectric poly(vinylidene fluoride) (PVDF) nanofilms have been fabricated by the Langmuir-Blodgett technique, possessing mainly a ferroelectric active phase and a controllable film thickness of 2.3 nm per layer. Atomic force microscopy and Fourier transform infrared spectroscopy were utilized to characterize the film properties. Importantly, the PVDF films could act as barrier layers to prepare spin transport devices using Fe3O4 and Co as bottom and top ferromagnetic electrodes, respectively. Spin-dependent electron transport behaviors were systemically studied in these devices by varying the PVDF film thickness from 3 layers (7 nm) to 13 layers (30 nm). With increasing PVDF layer numbers, the magnetoresistance (MR) response decreases likely due to the change in spin transport from tunneling to hopping transport. We further investigated the MR dependence on operation temperatures (150 K, 200 K, 250 K and 300 K). It is noteworthy that the MR effect was observed even at 300 K with an MR ratio exceeding 2.5%, which is achieved for the first time in such organic devices. The device performance could be further improved at lower operation temperatures. The MR ratios, device resistances and electron transport mechanisms in the present devices were also discussed to analyze the spin transport behaviors. The results indicate that the ferroelectric PVDF nanofilms are promising candidates for spin devices operated at room temperature, thereby shedding light on the design of organic ferroelectric spintronics with a higher performance.
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U2 - 10.1039/c7tc00517b
DO - 10.1039/c7tc00517b
M3 - Article
AN - SCOPUS:85021701585
VL - 5
SP - 5055
EP - 5062
JO - Journal of Materials Chemistry C
JF - Journal of Materials Chemistry C
SN - 2050-7526
IS - 21
ER -