In this work we verified how the chemical composition of the EC elements PMN-100xPT with x = 0, 0.1 in 0.35 influences the energy efficiency of an EC-cooling system. We showed that if no electric-energy or heat is regenerated, even small irreversibilities can cause a significant drop in the achievable energy efficiency. Therefore, due to the slim polarization-electric field hysteresis loops, the PMN – rich ceramics (x = 0, 0.1) are substantially more energy-efficient than the PMN-35PT ceramic, which experiences significant hysteresis losses.
COBISS.SI-ID: 14221083
The EC effect of the lead-free relaxor ferroelectric K[sub](0.5)Na[sub](0.5)NbO[sub]3-SrTiO[sub]3 (KNN-STO) ceramics was investigated. A large ΔTEC exceeding 1.2 K at 300 K and 1.9 K at 340 K was observed at 160 kV/cm in a broad temperature range of 80 K. Such a high ECE response near the room temperature is comparable to that found in lead-based ceramic materials, thus making KNN-STO a strong candidate to replace lead-based materials in future EC applications.
COBISS.SI-ID: 28581927
The electrocaloric effect (ECE), i.e., the conversion of the electric into the thermal energy has recently become of great importance for development of a new generation of cooling technologies. Here, we explore utilization of [Pb(Mg1/3Nb2/3)O3]0.9[PbTiO3]0.1 (PMN-10PT) relaxor ceramics as active elements of the heat regenerator in an ECE cooling device. We show that the PMN-10PT relaxor ceramic exhibits a relatively large electrocaloric change of temperature TEC )1 K at room temperature. The experimental testing of the cooling device demonstrates the efficient regeneration and establishment of the temperature span between the hot and the cold sides of the regenerator, exceeding several times the TEC within a single PMN-10PT ceramic plate.
COBISS.SI-ID: 13878299