Charge-induced spin polarization in non-magnetic organic molecule Alq${}_3$

Abstract

Electrical injection in organic semiconductors is a key prerequisite for the realization of organic spintronics. Using density-functional theory calculations we report the effect of electron transfer into the organic molecule Alq${}_3$. Our first-principles simulations show that electron injection spontaneously spin-polarizes non-magnetic Alq${}_3$ with a magnetic moment linearly increasing with induced charge. An asymmetry of the Al--N bond lengths leads to an asymmetric distribution of injected charge over the molecule. The spin-polarization arises from a filling of dominantly the nitrogen $p_z$ orbitals in the molecule's LUMO together with ferromagnetic coupling of the spins on the quinoline rings.

Accepted 4 pages 4 figures

References in corpus (1)

• Unravelling the role of the interface for spin injection into organic semiconductors

Cited by in corpus (2)

• A theoretical perspective on the modification of the magnetocrystalline anisotropy at molecule-cobalt interfaces
• Oxygen doping and polaron magnetic coupling in Alq${}_3$ films