Abstract
In order to test the hypothesis proposed in Reference 10 about a spontaneous relaxor-ferroelectric phase transition in PLZT (6-7)/65/35 the hysteresis loops and domain structure measurements were carried out. The results confirm this hypothesis. The appearance of the ferroelectric long range order in PLZT with decreasing concentration of La ions is explained by a larger coupling between the feroelectrically active BO6 octahedrons due to smaller concentration of defects and higher dielectric constant.