Giant magnetoresistance and spin Seebeck coefficient in zigzag a-graphyne nanoribbons

TL;DR

This study explores the spin-dependent electrical and thermoelectric properties of zigzag-graphyne nanoribbons, revealing giant magnetoresistance and tunable spin Seebeck effects influenced by doping and ribbon width.

Contribution

It demonstrates how doping and width control can manipulate magnetoresistance and spin Seebeck effects in zigzag-graphyne nanoribbons, advancing spintronic device design.

Findings

Giant magnetoresistance up to 10^6% in pristine even-width ZGNRs.

Doped odd-width ZGNRs exhibit large magnetoresistance.

B- and N-doped even-width ZGNRs show dominant spin Seebeck effect.

Abstract

We investigate the spin-dependent electric and thermoelectric properties of ferromagnetic zigzag-graphyne nanoribbons (ZGNRs) using the density-functional theory combined with the non-equilibrium Green's function method. A giant magnetoresistance is obtained in the pristine even-width ZGNRs and can be as high as 10e6 %. However, for the doped systems, a large magnetoresistance behavior may appear in the odd-width ZGNRs rather than the even-width ones. This suggests that the magnetoresistance can be manipulated in a wide range by the dopants on edges of ZGNRs. Another interesting phenomenon is that in the B- and N-doped even-width ZGNRs the spin Seebeck coefficient is always larger than the charge Seebeck coefficient, and a pure-spin-current thermospin device can be achieved at specific temperatures.