Abstract
X-ray, magnetic, and Mossbauer studies of a PbFe0.5Ta0.5O3 powder have been carried out. For the first time temperature dependence of the unit cell parameters was obtained. Antiferromagnetic Neel temperature TN ≈180 K was determined using the results of Mossbauer studies. In the vicinity of TN an anomaly in the temperature dependence of the monoclinic angle β was revealed in PFT. This anomaly seems to be due to the magnetoelectric coupling.