A simple model structure of the room-temperature magnetic semiconductor $\text{V}{\left(\text{TCNE}\right)}_2$ is proposed on the basis of available experimental data. The structural, electronic, and magnetic properties are investigated using hybrid-exchange density functional theory within periodic boundary conditions. A spin-polarized ferrimagnetic ground state with a total spin of $1{\mu }_B$ per formula unit is identified. The analysis of the corresponding electronic band structure and spin distribution reveals strong interactions between the V ions and the ${\left[\text{TCNE}\right]}^{\cdot -}$ radicals, identified as spin carrying units. Within a simple Ising Hamiltonian, a strong antiferromagnetic coupling between the metal and its nearest-neighbor ligands is predicted which is consistent with the observed high-temperature magnetic ordering. The computed results provide useful insight into the physical origin of the exceptional magnetic behavior of $\text{V}{\left(\text{TCNE}\right)}_2$.

• Received 2 December 2008

DOI:https://doi.org/10.1103/PhysRevB.79.085201