Journal ArticleDOI
Spin response in organic spin valves based on La 2 ∕ 3 Sr 1 ∕ 3 Mn O 3 electrodes
Reads0
Chats0
TLDR
In this article, the spin-valve magnetoresistance (MR) response at various biasing voltages and temperatures was investigated and shown to be asymmetric with respect to the voltage polarity.Abstract:
We fabricated spin-valve devices made of organic semiconductor thin films sandwiched between ferromagnetic half-metal ${\mathrm{La}}_{2∕3}{\mathrm{Sr}}_{1∕3}\mathrm{Mn}{\mathrm{O}}_{3}$ (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 $T\ensuremath{\sim}220\phantom{\rule{0.3em}{0ex}}\mathrm{K}$, similar to other MR responses in inorganic tunneling junction devices based on LSMO and Co ferromagnetic electrodes. In contrast, the spin-$\frac{1}{2}$ 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 $T\ensuremath{\sim}220\phantom{\rule{0.3em}{0ex}}\mathrm{K}$. 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.read more
Citations
More filters
Journal ArticleDOI
Spin routes in organic semiconductors
TL;DR: The main experimental results and their connections with devices such as light-emitting diodes and electronic memory devices are summarized, and the scientific and technological issues that make organic spintronics a young but exciting field are outlined.
Journal Article
Spin Routes in Organic Semiconductors
Journal ArticleDOI
Unravelling the role of the interface for spin injection into organic semiconductors
Clément Barraud,Pierre Seneor,Richard Mattana,Stéphane Fusil,Stéphane Fusil,Karim Bouzehouane,Cyrile Deranlot,Patrizio Graziosi,Luis E. Hueso,Ilaria Bergenti,Valentin Dediu,Frédéric Petroff,Albert Fert +12 more
TL;DR: In this paper, the metal/organic interface is found to be key for spin injection in organic semiconductors, and the authors investigated how to optimize the injection of spin into these materials.
Journal ArticleDOI
Isotope effect in spin response of pi-conjugated polymer films and devices.
Tho Duc Nguyen,Golda Hukic-Markosian,Fujian Wang,Leonard Wojcik,Xiaoguang Li,Eitan Ehrenfreund,Z. Valy Vardeny +6 more
TL;DR: It is demonstrated that the HFI does indeed have a crucial role in all three spin responses and OLED films based on the D-polymers show substantially narrower magneto-electroluminescence and ODMR responses, and OSV devices based on D- polymers show a substantially larger magnetoresistance.
Journal ArticleDOI
Direct measurement of the electronic spin diffusion length in a fully functional organic spin valve by low-energy muon spin rotation.
Alan J. Drew,J. Hoppler,J. Hoppler,Leander Schulz,Francis L. Pratt,P. Desai,P. Shakya,Theo Kreouzis,William P. Gillin,Andreas Suter,Nicola A. Morley,Vivek Kumar Malik,Adam Dubroka,Kyung Wan Kim,Houssny Bouyanfif,Francis Bourqui,Christian Bernhard,Robert Scheuermann,G. J. Nieuwenhuys,Thomas Prokscha,Elvezio Morenzoni +20 more
TL;DR: A new depth-resolved technique for measuring the spin polarization of current-injected electrons in an organic spin valve is presented and the temperature dependence of the measured spin diffusion length is correlated with the device magnetoresistance.
References
More filters
Journal ArticleDOI
Tunneling between ferromagnetic films
TL;DR: In this article, the mean magnetizations of the two ferromagnetic film are parrallel or antiparallel and conductance measurement is related to the spin polarizations of conduction electrons.
Journal ArticleDOI
Giant magnetoresistance in organic spin-valves
TL;DR: The injection, transport and detection of spin-polarized carriers using an organic semiconductor as the spacer layer in a spin-valve structure is reported, yielding low-temperature giant magnetoresistance effects as large as 40 per cent.
Journal ArticleDOI
Conditions for efficient spin injection from a ferromagnetic metal into a semiconductor
TL;DR: In this article, the authors adapt the spin accumulation model of the perpendicular transport in metallic magnetic multilayers to the issue of spin injection from a ferromagnetic metal (F) into a semiconductor (N) by introducing a spin dependent interface resistance (tunnel junction preferably) at the $F/N$ interfaces.
Journal ArticleDOI
Tunneling Conductance of Asymmetrical Barriers
TL;DR: In this paper, the voltage-dependent tunneling conductance of trapezoidal potential barriers has been calculated using two extreme models of WKB approximation and perfectly sharp boundaries between the metal electrode and the insulator.
Journal ArticleDOI
Nearly total spin polarization in La2/3Sr1/3MnO3 from tunneling experiments
Martin Bowen,Manuel Bibes,Alain Barthélémy,J.-P. Contour,Abdelmadjid Anane,Y. Lemaitre,Albert Fert +6 more
TL;DR: In this paper, a magnetoresistance ratio of more than 1800% is obtained at 4 K, from which they infer an electrode spin polarization of at least 95% and demonstrate the half-metallic nature of mixed-valence manganites and demonstrates their capability as a spin analyzer.