Solid solutions of 0-12 mol% nonferroelectric Ba(Sc1/2Nb1/2)O-3 (BSN),
Sr(Sc1/2Nb1/2)O-3 (SSN), Ca(Sc1/2Nb1/2)O-3 (CSN), and Cd(Sc1/2Nb1/2)O
-3 (CdSN) in ferroelectric Pb(Sc1/2Nb1/2)O-3 (PSN) are studied. The di
electric properties of these systems are highly dependent on the sinte
ring conditions. Equilibrium is apparently difficult to attain in thes
e systems. As a result, the ferroelectric phase transition is very bro
ad.