Electronic structure of ZrSiO₄ with interstitially doped V

Abstract

The electronic structure of V-doped ZrSiO₄ is estimated by using the generalized gradient approximation. When a V atom replaces a Zr or Si atom, localized V 3d states appear in the bandgap of ZrSiO₄. Four different supercells with V doped in the interstitial site of ZrSiO₄ are constructed by vacating one Si atom to satisfy the electroneutrality. When the Si near the doped V is vacant, the energy positions and splitting states of the V 3d states in the bandgap are almost identical to those when a V atom is substituted for a Si atom. By contrast, when the Si site away from the V is deficient, the characteristics of V 3d states in the bandgap are significantly different from those where V and Si are substituted. A comparison of the total energies of four supercells with interstitially doped V indicates that the total energy of the vacant Si site near the doped V is lower than that of the vacant Si site distant from V. Further, the total energy when interstitial V and Si vacancies are close to each other in the supercell is almost equal to that when Si and V are directly substituted. Therefore, the possibility that V substitutes not only the interstitial sites of ZrSiO₄ but also Si cannot be ruled out.