Hydrostatic pressure dependence on the collapsing of heptamer clusters in the charge ordered spinel AlV2O4

作者：Kalavathi S; Raju Selva Vennila; Chandra Sharat; Williams Quentin; Sahu P Ch

来源：Solid State Communications, 2017, 250: 23-27.

DOI：10.1016/j.ssc.2016.11.003

• Charge frustration
• Spinel AlV2O4
• Hydrostatic pressure
• ab-initio calculations

Charge frustrated spinels have engaged the interest of condensed matter studies due to the novel formation of multimer molecular sub units that lifts the degeneracy in the ground state. An exhaustive study on the stability of these molecular sub units is not available in the literature. In the present study, evidence has been obtained for the first time that hydrostatic pressure beyond 21 GPa, destabilizes the vanadium heptamer molecular sub units reversibly in the unique ambient temperature charge ordered spinel AlV2O4. The bulk modulus and its pressure derivative of the charge ordered phase are constrained. In addition a systematic structural analysis as a function of temperature shows destabilization of vanadium trimers those stack up to make the heptamer units. The crystal structure and total energy have been calculated using first principles density functional formalism (GGA approximation) as a function of pressure. The results obtained corroborate the stability of the frustrated phase beyond 20 GPa.

• 出版日期2017-1