Electronic structure and electron-transport properties of three metal hexacyanoferrates


Illustration of the sample and levels of stability

In this paper, Kevin Hurlbutt and his collaborators explored the electronic conductivities of Prussian blue analogs (PBAs).  Using density-functional theory, they modelled the electronic structure and the likely electron-conduction mechanism of manganese, iron and colbalt hexacyanoferrate in three oxidation states.  This study is an important foundation for making electronic conductivity a tunable PBA material property.

Published in Theoretical and Computational Chemistry, their paper 'Electronic structure and electron-transport properties of three metal hexacyanoferrates' demonstrates that the hybrid functionals reliably reproduced experimentally observed spin configurations and geometric phase changes.  The materials are confirmed as semiconductors or insu-lators with bandgaps ranging from 1.90 eV up to 4.94 eV.

The researchers then identified that most of the electronic band edges originated from carbon-coordinated-iron orbitals, which suggested that doping at the carbon-coordinated site might strongly affect carrier conductivity.

The final stage was to calculate the charge-carrier effective masses, which they found were very heavy.