Fig xA Linear fit of

The calculated value of Dr was found to amount −3.3% and was much smaller than 15% (an acceptable percentage difference in ionic radii between a doped and substituted ion). It suggests that the substitutional solid solutions AgY1−xGdx(WO4)2 could be formed easily in the whole concentration range of gadolinium ions. The substitution of Y3+ ions by the bigger one (Gd3+) leads to an increase in the lattice parameters of AgY1−xGdx(WO4)2 in comparison to the appropriate values for pure AgY(WO4)2 matrix.