An investigation of the effect of the nearest surroundings on the formation of V Lα emission bands for solid solutions of rare earth orthovanadates—orthophosphates

The V Lα, P Kβ and O Kα X-ray emission spectra for solid solutions YVO₄—YPO₄ and EuVO₄—EuPO₄ have been studied. It is shown that with an increase in concentration of orthophosphate in a substitutional solid solution a hump appears in the low energy part of the V Lα spectrum, corresponding in energy to the P Kβ spectrum. The cluster calculation of the electronic structure of solid solutions YVO₄—YPO₄, carried out by the Extended Hückel method, explains this effect as due to the hybridization of V 3d and P 3p states when PO₄ ] complexes are introduced into the orthovanadate tetrahedral lattice.