Remarkable modulation of the spin transport properties of transition metal dibenzotetraaza[14]annulenes by adsorption of oxygen

Here, the spin transport properties of molecular devices comprised of a transition metal-dibenzo-tetraaza[14]annulene complex (TM-DBTAA, TM=Co, Cu, Ni) connected to two single-walled carbon nan-otube (SWCNT) electrodes have been theoretically investigated by using the first-principles method. In addition, the effect of O2 adsorption on the TM atom on the spin transport properties of the investigated devices is inspected. The calculations reveal that Co-DBTAA behaves as a spin filter with SFE close to 100%. Upon O2 adsorption, the spin polarization of the current for Co-DBTAA is changed from spin-down to spin-up with the magnitude of SFE nearly unchanged. More interestingly, for the spin non-polarized and nonconducting Ni-DBTAA, the adsorption of an O2 molecule induces a spin-up polarized current with remarkable SFE larger than 90%. This work is helpful for future designing of molecular spin filters as well as gas sensors. (c) 2023 Elsevier B.V. All rights reserved.

Automated summary

In this study, the spin transport properties of molecular devices consisting of transition metal-dibenzo-tetraaza[14]annulene complex (TM-DBTAA, TM=Co, Cu, Ni) connected to carbon nanotube electrodes were investigated using first-principles method. It was found that Co-DBTAA acts as a spin filter with a spin filtering efficiency close to 100%. O2 adsorption on the TM atom results in a change of spin polarization for Co-DBTAA, while for Ni-DBTAA, it induces a spin-up polarized current with a high spin filtering efficiency. This work provides insights for the future design of molecular spin filters and gas sensors.