thank's for all

i have elaborated a FeCu, FeNi and FeCuNi for defferent Cu and NI powder , i have found the follow results:

1) crystallite size of FeCu is greather than FeCuNi than FeNi.

for FeCuNi for defferent Cu and NI powder, the crystallite size is the same. why ?

2) lattice strain of FeNi is greather than FeCuNi than FeCu.

for FeCuNi for defferent Cu and NI powder, the lattice strain for 10%of Ni is smaller than 15% and 20% but for 15% is maximum Why ?

3) for the the lattice parametre was max at 15% of Ni but 10% and 20% of the Ni is the same. Why ?