States of Atoms and Interatomic Interactions in Complex Perovskite-like Oxides: XVI.1 Spin State of Nickel(III) Atoms in YyLa1-yCaNixAl1-xO4 Solid Solutions by EPR and Magnetic Susceptibility Data

The EPR spectra of YyLa1-yCaNixAl1-xO4 solid solutions were studied. The simulated EPR spectra of low-spin Ni(III) atoms and the calculated specific integral intensity agree with magnetic susceptibility data, implying selective filling of octahedral sites by Ni(III) atoms and to non-monotone variation of the fraction of low-spin monomers on lanthanum substitution for yttrium.