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Transparent conductive oxides have attracted extensive attentions as a promising candidate for next-generation display materials. As a substitute for indium tin oxide, BaSnO3-based materials have been widely investigated with the improvement of electrical resistivity and optical transparency. Here, the effects of diverse rare-earth ions (R = La, Nd, Sm, Er) doping on the structural, electrical, and optical properties of RxBa1−xSnO3 films are systematically studied. The rare-earth ion doping improves the crystallinity of epitaxial RxBa1−xSnO3 films. And a rule for electrical performance optimization is revealed that the resistivity and metal-semiconductor transition temperature increase with increased atomic number of rare-earth ions. Further optimized composition for LaxBa1−xSnO3 is realized at x = 5% with the minimum resistivity of 0.31 mΩ cm. Moreover, all RxBa1−xSnO3 films exhibit a high transparency of greater than 90% in the visible region. This work demonstrates that among these four rare-earth ion doping, La-doping is the most effective approach to optimize the comprehensive properties of BaSnO3-based transparent conductive films. [ABSTRACT FROM AUTHOR]

Enhanced green and red upconversion emissions under 980 nm excitation are observed in Ba0.85−xCa0.15TiO3:0.75%Er3+/xIn3+ lead-free ferroelectric ceramics which were synthesized by solid state reaction method. With increasing In3+ ions doping level from x = 0% mol the green and red emission intensities increase and reach the maximum at x = 1.75% mol. The maximum intensity of green emission at 550 nm is 20 times larger than In3+ ions undoped samples, which is unprecedented for Er3+-doped perovskite ferroelectric materials. Based on the ultraviolet-visible-near infrared absorption spectra, the enhancement of the luminescence intensity of the A-site In3+ doped Ba0.85−xCa0.15TiO3:0.75%Er/xIn ceramics is attributed to In3+-doping-induced relative increase in isolate Er3+ and decrease in the clustered-Er3+. The effects of In3+ doping on the crystal structure, dielectric, ferroelectric, piezoelectric properties of the ceramics were also studied and discussed. [ABSTRACT FROM AUTHOR]

A series of In3+-doped Ba0.85Ca0.15TiO3:0.75%Er3+/xIn3+ (BCT:Er/xIn) lead-free piezoelectric ceramics with excellent upconversion luminescence were synthesized by the solid state reaction method. The effects of In3+ content on the crystal structure, ferroelectric, dielectric, piezoelectric, and upconversion luminescence properties were systematically studied. Under 980 nm excitation, a giant enhancement of the green emission (550 nm) by 10 times is achieved upon 2.5% mol In3+ doping, which is rarely observed in rare-earth ions-doped perovskite ferroelectric materials. The ultraviolet-visible-near infrared absorption measurements show that the In3+ doping may improve the dissolution of Er3+ ions and modify the isolate-/clustered-Er3+ ratio for x ≤ 2.5%, resulting in the enhancement of the absorption cross-section, thereby contributing to the enhancement of green luminescence. Unfortunately, the In3+ doping suppresses the ferroelectric and piezoelectric properties of the BCT:Er/xIn ceramics. This problem can be resolved by adding a small amount (1 mol%) of Yb3+ to the BCT:Er/xIn ceramics to restore their good ferroelectric and piezoelectric properties. Such In3+ and rare-earth ions co-doped ceramics with greatly enhanced upconversion luminescence and good ferroelectricity and piezoelectricity may have potential applications in electro-optical devices. [ABSTRACT FROM AUTHOR]

(1 − x)KNaLiNbSbO- xBiNaBaZrO [(1 − x)KNLNS- xBNBZ] (0 ≤ x ≤ 0.05) lead-free piezoelectric ceramics were prepared by using the conventional solid-state reaction method. The relationships among the composition, phase structure, phase volume fraction, microstructure, dielectric, ferroelectric, and piezoelectric properties as well as the phase diagram are established. Rietveld refinements of X-ray diffraction patterns show that with increasing doping level the volume fractions of the orthorhombic and tetragonal phases evolve from 58.7 and 41.3% for x = 0 to 1.7 and 98.3% for x = 0.05, which has strong impacts on the piezoelectric coefficient d and Curie temperature T . Upon the doping of BNBZ an orthorhombic-tetragonal ( O- T) phase boundary forms near room temperature, resulting in an optimum d ~ 288 pC/N, T ~ 305 °C, a converse piezoelectric coefficient d ~ 391 pm/V, and a field-induced strain S ~ 0.156% for the x = 0.035 ceramics. These results demonstrate that a balanced development of d and T can be realized by choosing suitable doping materials and content. [ABSTRACT FROM AUTHOR]

Here we report the structural, dielectric, ferroelectric, piezoelectric, and magnetic properties of zirconium-doped 0.67BiFeGaO-0.33BaZrTiO (BFG-BZT) lead-free ceramics. Structural investigations reveal that the doped Zr ions (up to x = 0.15) can be fully incorporated into the host lattice. Dielectric measurements demonstrate that with increasing Zr content, both the ferroelectric Curie temperature T and the dielectric constant decrease monotonously, and that the dielectric constant exhibits relaxor behaviors upon Zr doping. At the same time, the remnant polarization P increases and then decreases, with the maximum P ∼ 26 µC/cm for x = 0.025. One of the noteworthy results is that the remanent magnetic moment at room temperature increases up to 0.17 emu/g with increasing x from 0 to 0.15, which is attributed to enhanced lattice distortions due to Zr doping. The coexistence of strong ferroelectricity and ferromagnetism at room temperature implies that the BFG-BZT could be potential candidate materials for multiferroic device applications. [ABSTRACT FROM AUTHOR]