Relaxorlike dielectric dynamics in the lead-free K0.5Na0.5NbO3-SrZrO3 ceramic system

We have detected a typical relaxor/glasslike dielectric response in the derived lead-free (1−x)K0.5Na0.5NbO3-(x)SrZrO3 ceramic system. In the compositional range 0.10≤x≤0.33, where solid solubility was observed, the system exhibits a broad dispersive dielectric maximum, a Vogel–Fulcher temperature dependence of the characteristic relaxation frequency, and a paraelectric-to-glass crossover in the temperature dependence of the dielectric nonlinearity. As the relatively high values of the dielectric constant, exceeding 5000 in the x=0.15 compound, are only weakly dependent on the frequency in the range of 20 Hz–1 MHz, and, furthermore, the history-dependent effects play only a minor role in comparison to some widely used lead-based relaxors, this environmentally friendly system seems to be very promising for a variety of applications.