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Mn‐doped 0.36Pb(In1/2Nb1/2)O3–0.36Pb(Mg1/3Nb2/3)O3–0.28PbTiO3 [Mn‐PIMNT(36/36/28)] thin films were fabricated by pulsed laser deposition. The microstructures and ferroelectric, piezoelectric, dielectric, pyroelectric properties were investigated. The films exhibited a (111) orientation as well as a uniform and dense surface. The Raman spectra revealed that the films showed a rhombohedral phase at room temperature, rhombohedral to tetragonal, and tetragonal to paraelectric phase transitions near 150℃ and 250℃, respectively. Furthermore, the films exhibited a high remnant polarization (Pr) of 51.3 μC cm−2, a coercive field (EC) of 3.14 kV mm−1, a high normalized piezoelectric strain coefficient (d33∗) up to 47 pm V−1, a pyroelectric coefficient (p) up to 8.5 × 10−4 C m−2 K−1, and dielectric constant (εr) of 2824, as well as excellent dielectric tunability of 89% at room temperature. The excellent ferroelectric and pyroelectric properties combined with high Curie point indicate that the Mn‐PIMNT(36/36/28) films are a potential candidate for ferroelectric and pyroelectric devices. [ABSTRACT FROM AUTHOR]

A compensated pyroelectric infrared (PIR) detector based on Mn‐doped 0.15Pb(In1/2Nb1/2)O3‐0.55Pb(Mg1/3Nb2/3)O3‐0.30PbTiO3 (Mn‐PIMNT(15/55/30)) relaxor ferroelectric single crystal was theoretically designed and experimentally fabricated. Under the current‐mode amplification circuit, the voltage responsivity and specific detectivity of the compensated detector reached 8 × 104 V/W@10 Hz and 3.6 × 108 cm⋅Hz1/2/W, respectively. The noise mechanism of the detector was studied and the dominant noise sources at different frequencies were simulated. Even though the noise density of the compensated detector increased due to the introduction of the parallel compensation element, substantially enhanced signal stability was achieved and the compensated detector was much less susceptible to environmental temperature changes and vibrations, which is more suitable for application in harsh environments. [ABSTRACT FROM AUTHOR]

Optical properties of lead‐free ferroelectric pure and Mn‐doped 0.92Na0.5Bi0.5TiO3‐0.08K0.5Bi0.5TiO3 (NBT‐8KBT) single crystals have been investigated systematically. Refractive index and extinction coefficient were measured and the critical parameters are obtained by modified Sellmeier dispersion equations and single‐oscillator dispersion relation. The decline of refractive index for Mn:NBT‐8KBT could be related to the lattice distortion of the Mn ions doping. High transmittance (>70%) over the transparent region (>400 nm) was found in the pure NBT‐8KBT, higher than that of Mn:NBT‐8KBT, which could be caused by the increase of domain wall density. An about 100 nm red‐shift of absorption edge was observed in the Mn:NBT‐8KBT single crystal, which is located in the visible region. Optical bandgap energies calculated through Tauc equation and a large bandgap difference of 2.96 and 2.62 eV occurs in the NBT‐8KBT and Mn:NBT‐8KBT, respectively, which illustrates the modulation of the band structures by Mn doping. [ABSTRACT FROM AUTHOR]

Abstract: The pyroelectric properties of Mn‐doped Aurivillius ceramics with different pseudo‐perovskite layers were investigated. The pyroelectric coefficients for 0.2 wt% Mn‐doped two‐layer CaBi2Nb2O9 (CBN–Mn), three‐layer Bi4Ti2.85Nb0.15O12 (BTN–Mn), and four‐layer CaBi4Ti3.95Nb0.05O15 (CBTN–Mn) ferroelectric ceramics were found to be on the order of 26.0, 54.4, 84.4 μC/m2K at room temperature, respectively. These values were closely associated with the number of octahedral layers in the pseudo‐perovskite blocks. The high pyroelectric coefficient, together with low dielectric permittivity and loss (tan δ < 0.003), results in to high figures of merit for the current responsivity, voltage responsivity, and detectivity. The excellent pyroelectric properties and high Curie temperatures (TC > 660°C) make the Aurivillius ceramics potential candidates for pyroelectric devices over a broad temperature range. [ABSTRACT FROM AUTHOR]

A ternary solid solution (1 − x)(0.88 Bi0.5 Na0.5 TiO3-0.12 BaTiO3)- x Bi( Zn0.5 Ti0.5) O3 ( BNBZT, BNBZT x) was designed and fabricated using the traditional solid-state reaction method. The temperature and composition dependence of dielectric, ferroelectric, piezoelectric, and fatigue properties were systematically investigated and a schematic phase diagram was proposed. The substitution with Bi( Zn0.5 Ti0.5) O3 was found to shift the phase transition (ferroelectric tetragonal to relaxor pseudocubic phase) to lower temperatures. At a critical composition x of 0.05, large electric-field-induced strain response with normalized strain Smax /Emax as high as 526 pm/V was obtained under a moderate field of 4 kV/mm around room temperature. The strain exhibited good temperature stability within the temperature range of 25°C-120°C. In addition, excellent fatigue-resistant behavior was observed in the proposed BNBZT solid solution after 106 bipolar cycles. These give the BNBZT system great potential as environmental friendly solid-state actuator. [ABSTRACT FROM AUTHOR]

A ternary solid solution (0.935- x) Bi0.5 Na0.5 Ti O3-0.065 Ba Ti O3- x Sr Ti O3 was designed and fabricated using a conventional fabrication process. Temperature and composition dependence of the ferroelectric, dielectric, and piezoelectric properties were systematically investigated and a schematic phase diagram was established. The Sr Ti O3 substitution was found to induce a transition from ferroelectric to relaxor pseudocubic phases. Around a critical composition x of 0.22, large strain response of ~0.2% (under a moderate field of 4 kV/mm) with normalized strain of 490 pm/V was obtained. The large unipolar strain response would be of great interest for environmental-friendly 'on-off' actuators. [ABSTRACT FROM AUTHOR]

To prepare high-performance ferroelectric thin films on Si substrates for pyroelectric arrays applications, 0.74Pb(Mg1/3Nb2/3)O3-0.26PbTiO3 ( PMN-PT) thin films, with composition beyond morphotropic phase boundary, were deposited by radio-frequency magnetron sputtering. Conductive perovskite La0.6Sr0.4CoO3 with resistivity of about 20 μΩ cm was used as a buffer layer between PMN-PT and Pt/Ti/SiO2/Si substrates to promote perovskite phase formation for the PMN-PT thin films. The PMN-PT thin films with pure perovskite phase have been obtained at temperatures as low as 500°C, which is compatible with integrated circuits. The ferroelectric, dielectric, and pyroelectric properties of the films were investigated. It is found that the films exhibit a large remnant polarization of 29.2 μC/cm2 and a high pyroelectric coefficient of 9.4 × 10−4 C/m2 K at room temperature. The calculated figures of merit for current responsivity, voltage responsivity, and detectivity are 3.76 × 10−10 m/V, 0.02 m2/C, and 1.29 × 10−5 Pa−1/2, respectively. These features suggest the film a promising material for thermal imaging applications based on silicon technology. [ABSTRACT FROM AUTHOR]