Ferrimagnetism in 2D networks of porphyrin-X and -XO (X=Sc,...,Zn) with acetylene bridges

TL;DR

This study uses advanced computational methods to explore and identify ferrimagnetism in 2D networks of porphyrin-based molecules with transition metals, revealing how oxygen influences magnetic properties across different metals.

Contribution

It demonstrates the emergence of ferrimagnetism in 2D porphyrin networks with transition metals and oxygen, highlighting the long-range delocalized spin-polarization effects.

Findings

Oxygen decreases magnetism in first-half 3d transition metals.

Binding oxygen increases magnetic moments in second-half 3d transition metals and Sc.

Ferrimagnetism occurs in networks with V to Co transition metals, extended through acetylene bridges.

Abstract

Magnetism in 2D networks of the acetylene-bridged transition metal porphyrins M(P)-2(C-C)-2 (denoted P-TM), and oxo-TM-porphyrins OM(P)-2(C-C)-2 (denoted P-TMO), is studied with the density functional theory (DFT) and the self-interaction corrected pseudopotential scheme (pSIC). Addition of oxygen lowers magnetism of P-TMO with respect to the corresponding P-TM for most of the first-half $3d$-row TMs. In contrast, binding O with the second-half $3d$-row TMs or Sc increases the magnetic moments. Ferrimagnetism is found for the porphyrin networks with the TMs from V to Co and also for these cases with oxygen. This is a long-range effect of the delocalized spin-polarization, extended even to the acetylene bridges.