Spinel $\mathrm{Zn}{\mathrm{Mn}}_2{\mathrm{O}}_4$, which has a Jahn-Teller active ${\mathrm{Mn}}^{3+}$ ion, was reported to exhibit a first order structural phase transition under high pressure. The $c∕a$ ratio in the tetragonal structure reduces drastically from 1.62 to 1.10 at the transition pressure of $P_c\sim 23\mathrm{GPa}$. The transition was attributed to the change in the electronic configuration of Mn ions. Employing the full-potential linearized augmented plane wave band method, we have investigated the change of the electronic structure with varying both the volume and $c∕a$ ratio. Under high pressure, we have demonstrated the structural and the spin-state transition from a high-spin to a low-spin configuration of ${\mathrm{Mn}}^{3+}$.

• Received 2 August 2006

DOI:https://doi.org/10.1103/PhysRevB.74.172103