Phase transformation in rhombohedral lead metaniobate and in solid solutions on its base

Ceramics of rhombohedral lead metaniobate and solid solutions on its base with PbSb2O6, BiTiSbO6 and ''PbTiWO6'' has been produced via the solid-phase reactions. A phase transformation at 815+-10 deg C accompanied by compression has been discovered for the first time during the studies of thermal expansion of lead metaniobate ceramics. In the studied solid solutions the phase transformation temperature decreases with a growth in the secondary component concentration. The presence of piozoeffect in polarized PbNb2O6 ceramics and dielectric hysteresis loops in solid solutions on its base allows one to draw a conclusion on the ferroelectric nature of lead metaniobate low-temperature modification