Ferroelectric Devices

Effect of CuO on the sintering and cryogenic microwave characteristics of (Zr0.8Sn0.2)TiO4 ceramics

“…On the other hand, the extrinsic losses are caused by the extended dislocations, grain boundaries, porosity, oxygen vacancies and secondary phases [18]. These losses are caused mainly by the dipole relaxation of the defectoriented polarizations concentrated at the interfaces [19]. The unharmonicity terms in the potential energy when a pair of atoms is at mean separation decrease with decrease in temperature, which is in agreement with the second law of thermodynamics.…”

Pyroelectricity: From Ancient Curiosity to Modern Imaging Tool

“…9⊗12, 14 The pyroelectric current I generated per watt of input power, W 0 , is called the current responsivity, where p is the pyroelectric coefficient amplitude, h is the detector electrode absorptivity, A is the cross-sectional area of detector, w is the radiation modulation frequency, G is the thermal conductance to surroundings, and t T is the thermal time constant (to account for heat losses to surroundings). Multiplying the current responsivity by the impedance of the circuit produces the voltage responsivity, where t E is the electrical time constant (to account for RC losses in the circuit) and R T is the total resistance of the detector element and circuitry.…”

New Fe3+/ Cr3+ Perovskites with Anomalous Transport Properties: The Solid Solution LaxBi1–xFe0.5Cr0.5O3 (0.4 ≤ x ≤ 1)

“…3,12,13 Among other interesting results found for these materials, it is worth pointing out that they exhibit a semiconductor behavior with a temperature region of a "positive temperature coefficient" (PTC) for the resistivity. This can be potentially applied in devices such as temperature sensors or controllers, protection elements in circuits, or self-regulation smart devices; 14 actually, lead-free PTC resistors are already being used for such applications.…”

“…The synthesis of very pure polycrystalline powders has been successfully achieved at room pressure by a sol–gel method, and although the structure is quite simple, the transport properties appear to be intriguingly complex, especially in which concerns the magnetic properties, where ZFC curves are found to lie above the corresponding FC ones, a feature rarely observed. ,, Among other interesting results found for these materials, it is worth pointing out that they exhibit a semiconductor behavior with a temperature region of a “positive temperature coefficient” (PTC) for the resistivity. This can be potentially applied in devices such as temperature sensors or controllers, protection elements in circuits, or self-regulation smart devices; actually, lead-free PTC resistors are already being used for such applications.…”