Publication Type |
Journal Article |
School or College |
College of Science |
Department |
Physics |
Creator |
Vardeny, Zeev Valentine |
Other Author |
Wang, F. J.; Yang, C. G.; Li, X. G. |
Title |
Spin dynamics in organic spin valves based on La⅔Sr⅓MnO3 electrodes |
Date |
2007-06 |
Description |
We fabricated spin-valve devices made of organic semiconductor thin films sandwiched between ferromagnetic half-metal La2/3Sr1/3MnO3 (LSMO) and cobalt electrodes, using three different organic molecules. Subsequently, we studied the spin injection and transport properties by measuring the device magnetoresistance (MR) response at various biasing voltages V and temperatures T. We found that the spin-valve MR response in all devices monotonically decreases with V and is asymmetric with respect to the voltage polarity. We also found a steep MR decrease with T, where it vanishes at T~220 K, similar to other MR responses in inorganic tunneling junction devices based on LSMO and Co ferromagnetic electrodes. In contrast, the spin- /2 photoluminescence detected magnetic resonance of the organic interlayer, which directly depends on the spin-lattice relaxation rate of polarons in the organic semiconductor, was found to be temperature independent. We thus conclude that the steep MR dependence on T is due to the temperature dependence of the interfacial spin polarization of the LSMO electrode, which also drastically decreases up to T~220 K. We thus conclude that (i) the spin-lattice relaxation time in organic semiconductors should not be the limiting factor in fabricating room temperature organic spin valves, and (ii) in order to achieve room temperature spin-valve operation with substantial MR value, spin-injection electrodes other than LSMO need to be involved, having large and less temperature dependent spin polarization. |
Type |
Text |
Publisher |
American Physical Society |
Journal Title |
Physical Review B |
Volume |
75 |
Issue |
24 |
First Page |
245324 |
Last Page |
245321 |
DOI |
10.1103/PhysRevB.75.245324 |
citatation_issn |
1098-0121 |
Subject |
Spin dynamics; Organic spin-valves; Spin response; OSEC |
Subject LCSH |
Organic semiconductors -- Optical properties; Spin valves; Organic semiconductors -- Magnetic properties; Magnetoresistance |
Language |
eng |
Bibliographic Citation |
Wang, F. J., Yang, C. G., Vardeny, Z. V., & Li, X. G. (2007). Spin dynamics in organic spin valves based on La⅔Sr⅓MnO3 electrodes. Physical Review B, 75(24), 245324-1-7. |
Rights Management |
(c) American Physical Society http://dx.doi.org/10.1103/PhysRevB.75.245324 |
Format Medium |
application/pdf |
Format Extent |
203,917 bytes |
Identifier |
ir-main,10098 |
ARK |
ark:/87278/s6fx7tpd |
Setname |
ir_uspace |
ID |
703235 |
Reference URL |
https://collections.lib.utah.edu/ark:/87278/s6fx7tpd |