The cation substitutions in the crystal lattice of binary potassium-ho
lmium vanadate (V) K3Ho(VO4)(2) by magnesium have been studied using v
arious types of chemical solid state reactions. It was shown that in t
he presence of the quasi-ternary system K3VO4-Mg-3(VO4)(2)-HoVO4 at 70
0 degrees C there a compound defined as K3Ho(VO4)(2) with a narrow hom
ogeneity range where K and Ho are partially substituted by Mg in accor
dance with various schemes. (C) 1998 Published by Elsevier Science S.A
.