EPR of VO²⁺ in the Mineral Wavellite Al₃(OH)₃(PO₄)₂ · 5H₂O

Abstract

In wavellites from two different localities EPR spectra of V02+ ions were detected and analyzed. The most prominent center was axial within the limits of error with g = 1.932, gxx = gyy = 1.948, Azz = 171.8 and Axx = A = 54.7 (A in 10~4cm). The orientation of the z-axis proves that the Al -OH group with the shortest AI -O bond is substituted by the V02+ ion. Additional spectra of much lower relative intensity with different orientation of their z-axes can also be assigned to certain Al -O combinations.