Ferroelectric and magnetic phase transitions in multiferroic PbFe0.5Ta0.5O3-PbTiO3 solid solutions

Dielectric, X-ray, piezoelectric and Mossbauer studies of highly-resistive Li-doped (1-x)PbFe
_0.5
Ta
_0.5
O
₃
-(x)PbTiO
₃
ceramics from the 0<; x <;0.3 range fabricated by solid state synthesis and usual sintering have been carried out. Addition of PbTiO
₃
to PbFe
_0.5
Ta
_0.5
O
₃
increases the temperature T
_m
of the permittivity maximum, decreases the diffusion of this maximum and lowers the Neel temperature T
_N
. However above a certain compositional threshold fast lowering of T
_N
stops and a new magnetic state with comparatively high (~50 K) transition temperature becomes stable in a rather wide compositional range.