Investigation of organic magnetoresistance dependence on spin-orbit coupling using 8-hydroxyquinolinate rare-earth based complexes

Journal Article · Mon May 16 00:00:00 EDT 2016 · Applied Physics Letters

DOI:https://doi.org/10.1063/1.4950864· OSTI ID:22590680

Carvalho, R. S.; Ávila, H. C.; Costa, D. G. ^[1]; Paolini, T. B.; Brito, H. F. ^[2]; Capaz, Rodrigo B. ^[1]

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1. Instituto de Física, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Rio de Janeiro 21941-972 (Brazil)
2. Instituto de Química, Universidade de São Paulo, São Paulo, São Paulo 05508-000 (Brazil)

The recently discovered organic magnetoresistance effect (OMAR) reveals the spin-dependent behavior of the charge transport in organic semiconductors. So far, it is known that hyperfine interactions play an important role in this phenomenon and also that spin-orbit coupling is negligible for light-atom based compounds. However, in the presence of heavy atoms, spin-orbit interactions should play an important role in OMAR. It is known that these interactions are responsible for singlet and triplet states mixing via intersystem crossing and the change of spin-charge relaxation time in the charge mobility process. In this work, we report a dramatic change in the OMAR effect caused by the presence of strong intramolecular spin-orbit coupling in a series of rare-earth quinolate organic complex-based devices. Our data show a different OMAR lineshape compared with the OMAR lineshape of tris(8-hydroxyquinolinate) aluminum-based devices, which are well described in the literature. In addition, electronic structure calculations based on density functional theory help to establish the connection between this results and the presence of heavy central ions in the different complexes.

• OSTI ID: 22590680
• Journal Information: Applied Physics Letters, Vol. 108, Issue 20; Other Information: (c) 2016 Author(s); Country of input: International Atomic Energy Agency (IAEA); ISSN 0003-6951
• Country of Publication: United States
• Language: English

Related Subjects

71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
DENSITY
DENSITY FUNCTIONAL METHOD
ELECTRONIC STRUCTURE
EQUIPMENT
INTERACTIONS
L-S COUPLING
MAGNETORESISTANCE
ORGANIC SEMICONDUCTORS
RARE EARTHS
RELAXATION TIME
SPIN