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Abstract: BiScO3–PbTiO3 piezoelectric ceramics were fabricated by the conventional solid state reaction method. The effects of sintering atmosphere on microstructure and electrical properties of BiScO3–PbTiO3 were studied. Different weight changes were found in samples sintered in different atmospheres. X-ray diffraction analysis reveals that all the samples have perovskite structure and a second phase is observed in the samples sintered in sacrificial powders. EDS analysis suggests the second phase could be the compound containing Bi and Pb. Samples sintered in air show lower dielectric constant than those sintered in sacrificial powders, but a higher piezoelectric coefficient. The resisitivity of samples sintered in air is about one order of magnitude higher than that of those sintered in sacrificial powders. These results suggest a promising method to gain BiScO3–PbTiO3 high-temperature piezoceramics with excellent electromechanical properties. [Copyright &y& Elsevier]

Yttrium Iron Garnet (YIG) films were prepared on Si substrates by Chemical Solution Deposition (CSD) technique using acetic acid and deionized water as solvents. Well-crystallized and crack-free YIG films were obtained when annealed at 750 °C and 850 °C respectively, showing a low surface roughness of several nanometers. When annealed at 750 °C for 30 min, the saturated magnetization (Ms) and coercive field (Hc) of YIG films were 0.121 emu/mm 3 (4πMs = 1.52 kGs) and 7 Oe respectively, which were similar to that prepared by PLD technique. The peak-to-peak linewidth of ferromagnetic resonance (FMR) was 220 Oe at 9.10 GHz. The results demonstrated that CSD was an excellent technique to prepare high quality yttrium iron garnet (YIG) films on silicon, which could provide a lower-cost way for large-scale production on Si-based integrated devices. [ABSTRACT FROM AUTHOR]

Abstract: The ferroelectric hysteresis loops of (1− x)BiScO3–xPbTiO3 (BSPT) ceramics with different phase structure were measured under sinusoidal electric fields. Three-stage behaviors between ln〈A〉 (〈A〉 is hysteresis loop area) and ln E 0 (E 0 is the amplitude of field) were identified with the increasing of E 0. These three-stage behaviors reflected different polarization behavior in each stage, which were distinct from the existing two-stage behavior. The shifting of dividing points between two stages with the evolution of phase structure revealed that in the tetragonal phase domain switching has a higher activation field due to the different domain structure. [Copyright &y& Elsevier]

Abstract Bulk ceramics with high recoverable energy density (W re) and energy efficiency (η) play a critical role in the development of pulsed power systems for miniaturization and lightweight. The orthorhombic phase (Pb,La)(Zr,Ti)O 3 -based antiferroelectric (AFE) ceramics have been regarded as one of the most promising candidates for pulsed power system applications due to their relatively high energy storage density and efficiency. However, the main drawback of orthorhombic phase (Pb,La)(Zr,Ti)O 3 -based AFE ceramics is relatively low dielectric breakdown strengthen (DBS), which has always restricted the improvement of energy storage density. In this study, an effectively method to increase DBS by the introduction of Mn has been proposed. The relative density of orthorhombic phase (Pb 0.91 La 0.06)(Zr 0.96 Ti 0.04)O 3 (PLZT) ceramics was improved by Mn-doping. And the introduction of Mn can decrease the tolerance factor (t) of PLZT ceramics because the radius of Mn2+ is larger than that of B-site Zr4+/Ti4+, and thus enhancing antiferroelectricity. Meanwhile, the effects of Mn-doping on the phase structure, microstructure and dielectric properties of PLZT ceramics have been studied thoroughly in this study. It is found that the highest W re of 7.65 J/cm3 is obtained at 1.0 mol% Mn-doped PLZT ceramic, which is obviously larger than that of undoped PLZT ceramic (5.71 J/cm3). These results suggest that the Mn-doped PLZT ceramics are potential energy storage materials in pulsed power systems. Highlights • Enhanced the dielectric breakdown strengthen of pure antiferroelectric ceramics by Mn-doping. • Obtained a high recoverable energy density of 7.65 J/cm3 and relatively high η of 87% in Mn-doped antiferroelectric ceramics. • Better understanding of the mechanism on energy storage properties of Mn-doped antiferroelectric ceramics. [ABSTRACT FROM AUTHOR]

Abstract Pyroelectric energy harvesting has been attracting increasing attention due to its abundance and potential applications. In this work, we comparably investigated the pyroelectric properties of Pb 0.99 (Zr 0.95 Ti 0.05) 0.98 Nb 0.02 O 3 bulk ceramics without (PNZT95/5) and with Mn doping (PNMZT95/5). Compared to PNZT95/5, PNMZT95/5 demonstrated a lower dielectric constant and low rhombohedral - high rhombohedral ferroelectric phase transition temperature (T LH from 37 °C to 27 °C). Moreover, the poling time displayed significant effects on the dielectric and pyroelectric properties of the ceramics. A giant pyroelectric response was obtained for the PNMZT95/5 ceramics, of which the maximum pyroelectric figure of merit F E was 16017 J/(m3K2) after 180 min of poling, which increased 62% compared with the F E for PNZT95/5 (9890 J/(m3K2), far higher than those of other pyroelectric materials as well. PNMZT95/5 ceramics is suggested to be a promising candidate for the thermal energy harvesting applications. Highlights • Giant pyroelectric figure of merit was obtained at room temperature in PNZT95/5 ferroelectric ceramics by doping Mn. • Mn-doping decreased the F RL - F RH phase transition temperature of PNZT95/5 down to room temperature. • Prolonging the poling time of hard PNMZT95/5 ferroelectric ceramics could improve obviously the pyroelectric response. [ABSTRACT FROM AUTHOR]

Pb 0.99 (Sn x Zr 0.95− x Ti 0.05 ) 0.98 Nb 0.02 O 3 (PNZST( x ), 0.10 ≤ x ≤ 0.18) ceramics were fabricated by conventional solid state reaction method. Effects of tin (Sn) doping and its content x on their structure, phase transition behavior, and electrical properties were investigated. Analysis of X-ray diffraction patterns and Rietveld refinement results confirmed the crystal structures of different phases and also compositional driven phase transitions. The results indicated that with the increase in the value of x , orthorhombic phase was transformed into distorted tetragonal phase through rhombohedral phase. Ceramics exhibited the orthorhombic–rhombohedral phase coexistence for 0.10 ≤ x ≤ 0.16, and orthorhombic–rhombohedral–distorted tetragonal multiphase coexistence for x = 0.18. Although the orthorhombic antiferroelectric (AFE) phase was the major phase, no double hysteresis loops were detected through electrical hysteresis loop measurements because the electric field-induced AFE to ferroelectric (FE) phase transition occurred under the applied electric field, and the induced FE phase could not reverse back to AFE state after the removal of electric field. However, the trace of AFE behavior could be observed at a lower testing electric field. Moreover, increasing Sn content led to linear increment in phase transition temperature of FE RL -FE RH , up to 98.7 °C for x = 0.18. [ABSTRACT FROM AUTHOR]

Ca x Sr 0.3− x Ba 0.7 Nb 2 O 6 [CSBN ( x ), x = 0.00, 0.10, 0.20, and 0.30] lead-free ceramics were fabricated by traditional solid-state reaction technique. The morphology, structure, dielectric, ferroelectric and pyroelectric properties of CSBN ( x ) ceramics were systematically studied. The thermal depoling behaviors were evaluated through measurements of temperature dependence of piezoelectric constant ( d 33 ). All CSBN ( x ) ceramics exhibited obvious diffuse phase transitions and maximum dielectric constant (ε m ) increased monotonically with x . The ferroelectric and pyroelectric properties of CSBN ( x ) have been enhanced remarkably due to Ca addition. The remnant polarization ( P r ) and pyroelectric coefficient ( p ) of CSBN (0.30) samples reached 4.95 μC/cm 2 and 1.30 × 10 −8 C/cm 2 K which roughly tripled and doubled pure SBN. What's more, CSBN (0.20) samples achieved rather high pyroelectric figure of merit of voltage ( F v = 0.0203 m 2 /C) which is superior to many other lead-free materials and pyroelectric figure of merit of detectivity ( F D ) for CSBN (0.20) and CSBN (0.30) samples both soared to 0.61 × 10 −5 Pa −1/2 . The most inspiring part is the depoling temperature and Curie temperature noticeably shifted to higher temperature region owing to Ca addition. These results unveil the potential of CSBN ( x ) ceramics for infrared detector applications. [ABSTRACT FROM AUTHOR]

The composition dependent dielectric, ferroelectric and energy storage properties of tetragonal lead lanthanum zirconate stannate titanate (PLZST) antiferroelectric ceramics were systematically studied in this paper. Two sets of simple linear scaling relations were established for the forward switching field E AFE-FE , the backward switching field E FE-AFE and recoverable energy density W re . As Zr content increases (Ti fixed), E AFE-FE , E FE-AFE , W re decreases linearly, while the stored energy density W st declines first and then increases. In addition, decreasing Ti content (Zr fixed) leads to linear increments in all of E AFE-FE , E FE-AFE , W re and W st . These results not only reveal the superiority of PLZST with lower Zr and lower Ti contents for energy storage capacitors, but also provide a fast way to design PLZST ceramics with specific energy storage properties. Our work may also be very helpful for better understanding the mechanism of phase transition behaviors of antiferroelectric materials. [ABSTRACT FROM AUTHOR]

Optical phonons and phase transitions of (Pb 0.97 La 0.02 ) (Zr 0.60 Sn 0.40− y Ti y )O 3 (PLZST 97/2/60/40-100 y /100 y ) ceramics with different compositions have been investigated by x-ray diffraction and temperature dependent Raman spectra. From the temperature dependence of low wavenumber phonon modes, two phase transitions (antiferroelectric orthorhombic to intermediate phase and intermediate phase to paraelectric cubic phase) were detected. The intermediate phase could be the coexistence one of antiferroelectric orthorhombic and ferroelectric rhombohedral phase. In addition, two modes (a soft mode and an anharmonic hopping central mode) were found in the high temperature paraelectric cubic phase. On cooling, the anharmonic hopping central mode splits into two modes in the terahertz range. Moreover, the antiferrodistortive mode appears in the antiferroelectric orthorhombic phase. Based on the analysis, the phase diagram of PLZST ceramics can be well improved. [ABSTRACT FROM AUTHOR]