Thermally Stable Capacitive Energy-Density and Colossal Electrocaloric and Pyroelectric Effects of Sm-Doped Pb(MgNb)O-PbTiO Thin Films.

Sm-doped Pb(MgNb)O-PbTiO (Sm-PMN-PT) bulk materials have revealed outstanding ferroelectric and piezoelectric properties due to enhanced local structural heterogeneity. In this study, we further explore the potential of Sm-PMN-PT by fabricating epitaxial thin films by pulsed laser deposition, revealing that Sm doping significantly improves the capacitive energy-storage, piezoelectric, electrocaloric, and pyroelectric properties of PMN-PT thin films. These Sm-PMN-PT thin films exhibit fatigue-free performance up to 10 charge-discharge cycles and maintain thermal stability across a wide temperature range from -40 to 200 °C.

Giant switchable non thermally-activated conduction in 180° domain walls in tetragonal Pb(Zr,Ti)O.

Conductive domain walls in ferroelectrics offer a promising concept of nanoelectronic circuits with 2D domain-wall channels playing roles of memristors or synoptic interconnections. However, domain wall conduction remains challenging to control and pA-range currents typically measured on individual walls are too low for single-channel devices. Charged domain walls show higher conductivity, but are generally unstable and difficult to create.

Temperature Dependence of Dielectric Properties of Ferroelectric Heterostructures with Domain-Provided Negative Capacitance.

It is well known that the ferroelectric layers in dielectric/ferroelectric/dielectric heterostructures harbor polarization domains resulting in the negative capacitance crucial for manufacturing energy-efficient field-effect transistors. However, the temperature behavior of the characteristic dielectric properties, and, hence, the corresponding behavior of the negative capacitance, are still poorly understood, restraining the technological progress thereof. Here we investigate the temperature-dependent properties of domain structures in the SrTiO/PbTiO/SrTiO heterostructures and demonstrate that the temperature-thickness phase diagram of the system includes the ferroelectric and paraelectric regions, which exhibit different responses to the applied electric field.