P406
A Theoretical Model for the Phase Transition Mechanism in Cobalt-Iron Cyanide
Tohru Kawamoto, Yoshihiro Asai and Shuji Abe
Electrotechnical Laboratory
A mechanism is proposed for heat-induced charge transfer from iron to cobalt in the phase
transition of prussian blue-type compound with suggestion of the experimental approach to
confirm.
The charge transfer is caused in our model by the energy level crossing of the
Fe-$d\varepsilon$ and Co-$d\gamma$ orbital owing to the elongation of distance between cobalt
and nitrogen.
First principles band structure calculation is carried out in order to estimate the dependence
of $d$-energy level on the elongation.
In addition, it is proposed that the existence of water molecules make the transition easy by
decreasing the effect of crystal field at cobalt site ,which is simulated by the ab-initio
molecular orbital calculation for the metal cyanide cluster.
We also discuss about the possibility that photo-induced magnetic transition can realize in the
same mechanism.
Return to Program.