2025/06/20 by Granzow, T., Aravindhan, A., Nouchokgwe, Y. +9
#Applied Physics (physics.app-ph) #FOS: Physical sciences #Materials Science (cond-mat.mtrl-sci)
paper · doi:10.48550/arxiv.2506.17126
Ferroelectrics show a phase transition to a paraelectric phase at a well-defined transition temperature. Introducing disorder makes this transition diffuse, and the system becomes a relaxor. Since the degree of (dis-)order is usually manipulated by varying the chemical composition, it is difficult to establish a direct relationship between disorder and the degree of diffuseness. Perovskite structured lead scandium tantalate (Pb[Sc1/2Ta1/2]O3, PST) offers the opportunity to tune the character of the transition by thermal annealing without changing the stoichiometry. Here it is demonstrated that there is a linear correlation between the structural ordering, quantified by the intensity ratio S of the pseudocubic (111)/(200) x-ray diffraction peaks, and the diffuseness parameter γ deduced from temperature-dependent dielectric spectroscopy. The relation is universal, independent of whether the sample is a thin film, multilayer capacitor or bulk ceramic, and also independent of the absolute value of the dielectric permittivity.