Design of a defect-induced orange persistent luminescence phosphor BaZnGeO4:Bi3+

We report a novel bright orange persistent luminescence (PersL) phosphor BaZnGeO₄:Bi³⁺ with broad emission and PersL spectra. Its crystal structure, photoluminescence (PL) spectra, thermoluminescence (TL) spectra and PersL spectra were investigated in detail. The two emission bands at 440 nm and 595 nm originate from Bi³⁺ ions in normal Ba²⁺ sites (Bi1) and Ba²⁺ sites close to vacancy defects (Bi2), respectively. The introduction of and defects improves the emission intensity of Bi2 more than that of Bi1, demonstrating that Bi2 is related to the vacancy defects. The orange emission and PersL properties of BZGO:Bi³⁺ can be improved when a little and defects are introduced, because the introduction of and defects makes it easier for Bi³⁺ to enter in Ba²⁺ sites; and for PersL, and defects can perform as the effective trap centers to capture more charges, which is beneficial for PersL. BZGO:Bi³⁺ has quite good thermal stability, and the bright orange PersL can be observed by the naked eye for 1 h. Finally, a feasible PersL mechanism of BZGO:Bi³⁺ was proposed to clarify the PersL-generation process.     

Toward temperature-dependent Bi3+-related tunable emission in the YVO4:Bi3+ phosphor

Up until now, many previous works have indicated us that the photoluminescence (PL) properties of phosphors sometimes can be changed with the change in the external temperature, resulting in the anomalous PL phenomena and correlated new applications that are difficult to achieve at room temperature. In this work, we report the temperature-dependent Bi³⁺-related PL properties in the YVO₄:Bi³⁺ phosphor. Our findings show that increasing the temperature from 10 to 300 K enables manipulating the energy interaction from groups to Bi³⁺, thereby leading to the temperature-induced color tuning from blue (0.183, 0.212) to yellow (0.418, 0.490). Upon this heating process, we further reveal that the dynamic Bi³⁺ luminescence has experienced a regular transition from double-exponential to single-exponential decay, which results in the decrease in the average Bi³⁺ lifetime from 122.606 to 0.376 μs. Discussions on the PL results imply that the tunable PL observations are due to the interplay of temperature-dependent energy transfer from groups to Bi³⁺ and redistribution of the excited ³P₀ and ³P₁ states of Bi³⁺ upon the thermal stimulation. This work not only presents the temperature-triggered Bi³⁺ tunable properties in the well-studied YVO₄ host lattice but also can provide new insights into revealing Bi³⁺-related PL mechanism in other Bi³⁺-doped photonic materials in the future and, in the meanwhile, gives some directive ideas for us to explore previously unnoticed applications for rare-earth (RE; eg, Eu³⁺, Pr³⁺, Tb³⁺, Eu²⁺, Er³⁺, etc) and other non-RE (eg, Bi³⁺, Mn⁴⁺, Mn²⁺, Cr³⁺, etc) doped phosphors.     

Enhanced Light Storage of SrAl2O4 Glass‐Ceramics Controlled by Selective Europium Reduction

A luminescent Eu, Dy: SrAl₂O₄ glass‐ceramics with high transparency in the visible region was successfully synthesized using the frozen sorbet technique with the control of O₂ partial pressure () for the oxidation of Eu²⁺ ions. The glass‐ceramics include Eu²⁺, Eu³⁺, and Dy³⁺ ions, and thus exhibits three characteristic types of emission bands, 4f–5d at around 520 nm (Eu²⁺ ions), 4f–4f at 610 nm (Eu³⁺ ions), and 480 nm (Dy³⁺ ions). The Eu, Dy: SrAl₂O₄ glass‐ceramics provide remarkable long‐persistent luminescence under dark condition. The glass‐ceramics also exhibits color‐changing luminescence in the visible region based on their remarkable light storage properties. The luminescent Eu, Dy: SrAl₂O₄ glass‐ceramics using the frozen sorbet technique with control of are promising materials for application in novel photonic and light storage materials.     

Role of oxygen-vacancy in piezoelectric properties and fatigue behavior of (Bi0.5Na0.5)0.93Ba0.07Ti1+xO3 ceramics

In this reported study, (Bi_0.5Na_0.5)_0.93Ba_0.07Ti_1+xO₃ (abbreviated as BNBT_1+x) ceramics, containing Ti-nonstoichiometry that ranged from a 2% deficiency to a 1% excess, were designed and systematically characterized. The results of the X-ray diffraction Rietveld refinement and X-ray photoelectron spectroscopy analysis of these materials revealed that the amount of Ti in the BNBT_1+x ceramics significantly affected the degree of coexistent rhombohedral/tetragonal phases and also affected the content of singly/doubly charged oxygen-vacancy (/) in the ceramics. After poling and 10⁵ fatigue cycles, the variation in Raman resonance line-width of the Ti–O bond in the BNBT_1+x ceramics was found to be strongly dependent on the amount of Ti in the ceramic. The → transformation and clustering of the defects under electrical loading were considered to be a critical factor in electric field-induced structural transition and fatigue properties of the material.     

Thermoelectric properties and phase transition of doped single crystals and polycrystals of Bi2Te3

The temperature dependences of the electrical conductivity , Seebeck coefficient , and heat capacity C_p(T) of polycrystalline samples of Bi₂Te₃, Bi₂Te₃+1%CuI, and Bi₂Te₃+1%(CuI+1/2Pb) are investigated in the temperature range below room temperature. Based on the temperature dependences of all investigated physical properties, it is discovered that phase transition occurs at 120–200 K. Investigation of single crystals shows that anomalies in the electrical resistivity occur only across the crystal growth axis (across the well-conducting Bi–Te plane). Investigation of the low-temperature dependence of electrical conductivity shows that all polycrystalline samples exhibit quasi-two-dimensional electron transport. Additionally, quasi-two-dimensional transport is detected in single crystals based on anisotropy analysis (where is the resistivity along the crystal growth axis, and is resistivity across the crystal growth axis) and temperature dependence below 50 K. The Fermi energy is estimated using the temperature dependence of . It is discovered that an increase in at T > 200 K is associated with the phase transition. For single-crystal samples, the maximum thermoelectric figure of merit ZT, as observed along the crystal growth axis, increases with doping. A maximum ZT value of ∼1.1 is observed for the Bi₂Te₃+1%(CuI+1/2Pb) sample at room temperature ().     

Enhanced spontaneous polarization in double perovskite Bi2FeCrO6 films

We report the pulsed-laser deposition of epitaxial double-perovskite Bi₂FeCrO₆ (BFCO) films on the (001)-, (110), and (111)-oriented single-crystal SrTiO₃ substrates. All of the BFCO films with various orientations show the and superlattice-diffraction peaks. The intensity ratios between the -superlattice and the main 111-diffraction peak can be tailored by simply adjusting the laser repetition rate and substrate temperature, reaching up to 4.4%. However, both optical absorption spectra and magnetic measurements evidence that the strong superlattice peaks are not correlated with the B-site Fe³⁺/Cr³⁺ cation ordering. Instead, the epitaxial (111)-oriented Bi₂FeCrO₆ films show an enhanced remanent polarization of 92 μC/cm² at 10 K, much larger than the predicted values by density-functional theory calculations. Positive-up-negative-down (PUND) measurements with a time interval of 10 μs further support these observations. Therefore, our experimental results reveal that the strong superlattice peaks may come from A- or B-site cation shifts along the pseudo-cubic [111] direction, which further enhance the ferroelectric polarization of the BFCO thin films.     

Microstructure of mayenite 12CaO·7Al2O3 and electron emission characteristics

Electron emission characteristic, electrical conductivity of polycrystalline mayenite (12CaO·7Al₂O₃) electride, formation of [Ca₂₄Al₂₈O₆₄]⁴⁺(e⁻)₄ framework as a function of phase content, and microstructure have been investigated. The mayenite microstructure was investigated using high-resolution transmission microscopy which revealed the type cage structure of 12CaO·7Al₂O₃ partially filled by extra-framework oxygen ions. Incorporation of electrons by means of carbon ion template 12CaO·7Al₂O₃ produces complex structure, and an incomplete ion template 12CaO·7Al₂O₃ structure consisting of mixture of a [Ca₂₄Al₂₈O₆₄]⁴⁺(e⁻)₄ and [Ca₂₄Al₂₈O₆₄]⁴⁺(O²⁻)₂ framework had a direct effect on the electron emission. Surface chemistry and stability of the 12CaO·7Al₂O₃ electride have been studied using x-ray photoelectron spectroscopy. The work function of phase pure 12CaO·7Al₂O₃ electride was determined from direct thermionic emission data and compared to the measurement from ultraviolet photoelectron spectroscopy (UPS). Depending on the extent of ion template of 12CaO·7Al₂O₃ structure, a work function of 0.9–1.2 eV and 2.1–2.4 eV has been measured and thermionic emission initiating at 600°C.     

Optical transition properties,internal quantum efficiencies,and temperature sensing of Er3+ doped BaGd2O4 phosphor with low maximum phonon energy

The hosts with low maximum phonon energy (MPE) are preferred since the nonradiative consumption of the luminescence centers in them are low. Among the low MPE hosts, the oxide ones are more favored owing to their excellent stability and easy synthesis. In this work, the optical and spectroscopic properties of BaGd₂O₄:Er³⁺ phosphor were studied. The MPE of BaGd₂O₄ host was observed from Eu³⁺ phonon sideband (PSB) spectrum and Raman spectrum to be 477 cm⁻¹ which does not second to the fluoride hosts. The refractive index, which is indispensable for Judd–Ofelt calculation, was confirmed from the both approaches of the Eu³⁺-probe and the band gap energy, and the similar refractive indices were confirmed, therefore the average refractive index 2.01 was used in the Judd–Ofelt calculation. The Judd–Ofelt parameters of Er³⁺ in BaGd₂O₄ host was confirmed to be = 7.91 × 10⁻²¹ cm², = 2.36 × 10⁻²¹ cm², and = 9.00 × 10⁻²² cm². Furthermore, the internal quantum efficiencies for ⁴F_9/2 and ⁴I_J (J = 9/2, 11/2, and 13/2) levels were determined. Finally, the optical temperature sensing properties were studied in detail, and the temperature calibration curve was experimentally derived, meanwhile the maximum absolute sensitivity was confirmed to be 0.0028 K⁻¹.     

Flash sintering produces eutectic microstructures in Al2O3–LaPO4 versus conventional microstructures in 8YSZ–LaPO4

While monazite (LaPO₄) does not flash sinter even at high fields of 1130 V/cm and temperatures of 1450°C, composite systems of 8YSZ–LaPO₄ and Al₂O₃–LaPO₄ have been found to more readily flash sinter. 8YSZ added to LaPO₄ greatly lowered the furnace temperature for flash to 1100°C using a field of only 250 V/cm. In these experiments, -Al₂O₃ alone also did not flash sinter at 1450°C even with high fields of 1130 V/cm, but composites of Al₂O₃–LaPO₄ powders flash sintered at 900-1080 V/cm at 1450°C. Alumina–monazite (Al₂O₃–LaPO₄) composites with compositions ranging from 25 vol% to 75 vol% Al₂O₃ were flash sintered with current limits from 2 to 25 mA/mm². Microstructures were evaluated by scanning electron microscopy (SEM) and transmission electron microscopy (TEM). A eutectic microstructure was observed to form in all flash sintered Al₂O₃–LaPO₄ composites. With higher power (higher current limits), eutectic structures with regular lamellar regions were found to coexist in the channeled region (where both the current and the temperature were the highest) with large hexagonal-shaped -Al₂O₃ grains (up to 75 m) and large irregular LaPO₄ grains. With lower power (lower current limits), an irregular eutectic microstructure was dominant, and there was minimal abnormal grain growth. These results indicate that Al₂O₃–LaPO₄ is a eutectic-forming system and the eutectic temperature was reached locally during flash sintering in regions. These eutectic microstructures with lamellar dimensions on the scale of 100 nm offer potential for improved mechanical properties.     

Near‐Infrared Broadband Photoluminescence of Bismuth‐Doped Zeolite‐Derived Silica Glass Prepared by SPS

Through the order–disorder transition process of zeolites, bismuth‐doped zeolite‐derived silica glasses with broadband near‐infrared (NIR) photoluminescence have been successfully prepared by spark plasma sintering (SPS). The samples were characterized by X‐ray diffraction, UV‐vis, photoluminescence, and fluorescence lifetime. The results showed that as‐prepared samples possessed favorable broadband NIR luminescence. The NIR emission (peaked at ~1140 nm) intensity decreased with increasing the bismuth doping concentration when excited by 500 and 700 nm. The tendency was different from the emissions (peaked at ~1240 nm) excited by 800 nm. In addition, the NIR fluorescence peaks of the fixed Bi concentration sample can be observed almost around 1140 or 1240 nm when excited by different wavelengths from 500 to 950 nm. These phenomena implied that the NIR emission peaked at different wavelengths may originate from different bismuth species. Three kinds of Bi active centers Bi⁺, Bi⁰, and (Bi₂)^2? were proposed to contribute to the NIR emission peaks at ~1140, 1240, and 1440 nm, respectively. Interestingly, a broadband NIR emission peaked at 1207 nm with a full‐width at half maximum of 273 nm was observed when excited by 600 nm, whose intensity was stronger than that excited by 800 nm. This property might be useful for broadband fiber amplifiers and tunable lasers.     

Crystal structure,phonon modes,and bond characteristics of AgPb2B2V3O12 (B = Mg,Zn) microwave ceramics

AgPb₂B₂V₃O₁₂ (B = Mg, Zn) ceramics with low sintering temperature were synthesized via the conventional solid-state reaction route. Rietveld refinements of the X-ray diffraction patterns confirm cubic symmetry with space group . The number of observed vibrational modes and those predicted by group theoretical calculations also confirm the space group. At the optimum sintering temperature of 750°C/4 hours, AgPb₂Mg₂V₃O₁₂ has a relative permittivity of 23.3 ± 0.2, unloaded quality factor () of 26 900 ± 500 GHz (), and temperature coefficient of resonant frequency of 19.3 ± 1 ppm/°C, while AgPb₂Zn₂V₃O₁₂ has the corresponding values of 26.4 ± 0.2, 28 400 ± 500 GHz () and –18.4 ± 1 ppm/°C at 590°C/4 hours. Microwave dielectric properties of a few reported garnets and Pb₂AgB₂V₃O₁₂ (B = Mg, Zn) ceramics were correlated with their intrinsic characteristics such as the Raman shifts as well as width of A_1g Raman bands. Higher quality factor was obtained for lower full width at half-maxima (FWHMs) values of A_1g modes. The increase in B-site bond valence contributes to high and low |τ_f| with the substitution of Zn²⁺ by Mg²⁺. Furthermore, the high ionic polarizability and unit cell volume with Zn²⁺substitution contribute to increased relative permittivity.     

Role of vanadium oxide on the lithium silicate glass structure and properties

The structural role of V in 28Li₂O–72SiO₂ (in mol%) lithium silicate glass doped with 0.5 mol% V₂O₅ was assessed using ²⁹Si and ⁵¹V Nuclear Magnetic Resonance (NMR), Fourier-transform infrared (FTIR), and X-ray photoelectron (XPS) spectroscopy techniques. Despite the low amount of V₂O₅ used, the structural information obtained or deduced from the statistical analysis of the NMR data could explain the evolution of glass properties after V₂O₅ addition. The XPS results indicated that all vanadium exists in 5+ oxidation state. Both the ²⁹Si NMR and FTIR data point toward an increase in the polymerization of the silicate network, caused by the V₂O₅ acting as network former, capable to form various tetrahedral units (for n = 0, 1, and 2) in the glasses. These units, which are similar to phosphate units, scavenge the Li⁺ ions and cause the silicate network to polymerize. However, in an overall balance, the entire glass network is depolymerized due to the additional nonbridging oxygens contributed by the vanadium polyhedra. The addition of vanadium causes the network to expand and increases the ionic conductivity.     

Fabrication and characterization of tetragonal yttria-stabilized zirconia single-crystalline thin film

Tetragonal yttria-stabilized zirconia thin film was successfully fabricated by a pulsed laser deposition method. The thin film grew heteroepitaxially with the orientation relationship of ZrO₂‖Al₂O₃. Energy dispersive X-ray spectroscopy mapping revealed that Y³⁺ ions were distributed homogeneously without local segregations. X-ray and electron-diffraction analysis confirmed a single crystalline structural feature of the film. On the other hand, high-resolution scanning transmission electron microscopy observations show that this film contains small-angle tilt grain boundaries, which is composed of the periodic array of dislocations with the Burgers vector .     

Effect of Al2O3 on the formation of color centers and CdSe/Cd1−xZnxSe quantum dots in SiO2–Na2O–ZnO glasses

color centers and CdSe/Cd_1−xZn_xSe quantum dots (QDs) were formed in silicate glasses, respectively, by carefully adjusting the content of Al₂O₃. The absorption coefficient and broad visible emission at 400-700 nm of color centers increased firstly and then decreased upon increasing concentration of Al₂O₃ from 0 to 5 mol. %. With 2 mol. % Al₂O₃ adding, the band edge emission centered at 497 nm from CdSe QDs in glasses was observed after heat treatment. Raman spectra and TEM characterization confirmed the formation of CdSe/Cd_1−xZn_xSe QDs. The small amount addition of Al₂O₃ had a significant effect on the formation of color centers and precipitation of CdSe/Cd_1−xZn_xSe QDs in glasses due to its complicated effect on the network structure and optical basicity of the glasses.     

Effect of Oxygen Vacancy on Electrical Property of Acceptor Doped BaTiO3–Na0.5Bi0.5TiO3–Nb2O5 X8R Systems

In this study, we reported a new BaTiO₃–Na_0.5Bi_0.5TiO₃–Nb₂O₅–Mn₂O₃/Fe₂O₃/Co₃O₄/In₂O₃ X8R system with high dielectric constant (>2100) at room temperature. The impacts of oxygen vacancy ( ) on dielectric, electrical conductivity, and ferroelectric properties were systematically studied. The Curie point is largely depended on the concentration, which can be confirmed by the dielectric behavior and A_1g octahedral breathing modes in Raman spectrum. In addition, the activation energy of diffusion is greatly reduced with the increase in concentration. It was found that the remnant polarization and coercive field were both decreased with increasing concentration, due to the facilitated defect dipoles reorientation and domain switching.     

Giant electro-strain in textured Li+-doped 0.852BNT–0.11BKT–0.038BT ternary lead-free piezoelectric ceramics

Texturing is an effective approach to improving the piezoelectricity of piezoelectric ceramics. In this work, <001> textured Li⁺-doped 0.852Bi_0.5Na_0.5TiO₃–0.11Bi_0.5K_0.5TiO₃–0.038BaTiO₃ ternary lead-free piezoelectric ceramics are prepared by the reactive templates grain growth (RTGG) method. X-ray diffraction (XRD) results demonstrate a high orientation degree of 77% along the <001> direction. Outstanding electro-strain response, which is higher than most of reported BNT-based textured ceramics, is achieved due to the contribution of oriented-grains along the <001> direction. A large electro-strain of 0.55% with a relatively low hysteresis is obtained at 6.5 kV/mm with corresponding large signal piezoelectric coefficient () of 846 pm/V in the textured ceramics, which is 49% higher than that of the random ceramics. Besides, the electro-strain could reach as high as 0.52%@5.5 kV/mm ( = 945 pm/V) at 100°C. These results indicate that the RTGG is an effective way to design high performance lead-free piezoelectric materials.     

Thermodynamic properties of PrRhO3 and phase diagrams of the system Pr–Rh–O

A solid-state electrochemical cell with yttria-stabilized zirconia (YSZ) as the electrolyte is used to measure accurately thermodynamic properties of PrRhO₃ in the range of temperature from 875 to 1325 K. The standard Gibbs energy of formation of PrRhO₃ with orthorhombically distorted perovskite structure from its binary oxides β-Rh₂O₃ and hexagonal Pr₂O₃ is given by, . Invoking the Newmann-Kopp rule, the standard enthalpy of formation from elements and standard entropy of PrRhO₃ at 298.15 K are evaluated: and . Phase relations in the system Pr–Rh–O at 1200 K are computed from thermodynamic data. Calorimetric data on enthalpy of formation of two intermetallic compounds are combined with the semi-empirical model of Miedema and phase diagram to estimate Gibbs energy of formation for the intermetallics and liquid alloys. An isothermal section of ternary phase diagram, an oxygen potential-composition diagram in 2-D and a 3-D chemical potential diagram for the system Pr–Rh–O at 1200 K are presented. In addition, temperature-composition diagrams at different oxygen pressures are developed. The diagrams provide a road map for design and optimization of processing routes for catalysts based on Rh.     

Room-temperature mechanochemical synthesis of RE molybdates: Impact of structural similarity and basicity of oxides

The feasibility of room-temperature synthesis of R₁₀Mo₂O₂₁ (R = La, Y, Er) molybdates via mechanochemical processing of the 5R₂O₃+2MoO₃ oxide mixtures has been studied using X-ray powder diffraction (XRD) with Rietveld refinement and electron spin resonance spectroscopy (ESR). In all systems, the initial stage of mechanochemical synthesis is associated with MoO₃ dissolution in R₂O₃ despite the difference in the crystal structure of initial oxides: La₂O₃ (, no. 164), Er₂O₃ and Y₂O₃ (, no. 206). Only for the 5Er₂O₃ + 2MoO₃ system containing magnetic cations, ESR detects A-type Mo⁵⁺ centers, thus enabling to follow the decrease in MoO₃ content during room-temperature mechanochemical synthesis. In the Er- and Y-based systems, the starting oxides and synthesized R₁₀Mo₂O₂₁ (R = Y, Er) molybdates have the same bixbyite structure and mechanochemical MoO₃ dissolution in these oxides leads to R₁₀Mo₂O₂₁ synthesis at room temperature within 80 min. In the La-based system, MoO₃ dissolution leads mainly to mechanochemical synthesis of La₁₀Mo₂O₂₁ with the same structure as the starting La₂O₃ (, no. 164), but the amorphization of La₂O₃ and formation of basic lanthanum hydroxide during milling also took place. The use of nanosized MoO₃ facilitates the slightly formation of La₁₀Mo₂O₂₁ (, no. 164), but makes no impact on the synthesis of La₁₀Mo₂O₂₁ ( (RI), no. 166).     

Microwave and terahertz properties of porous Ba4(Sm,Nd,Bi)28/3Ti18O54 ceramics obtained by sacrificial template method

Microwave and terahertz communications are increasingly significant, however, the lack of material information in terahertz band limits their development. Moreover, few lightweight materials with a high relative dielectric constant () are found suited for satellite communication and wearable devices. In this study, we developed lightweight porous Ba₄[(Sm_0.1Nd_0.9)_0.9Bi_0.1]_28/3Ti₁₈O₅₄ (BSNBT) ceramics exhibiting a total porosity ranging from 6.3% to 26.5% (bulk density ranging from 5.47 to 4.29 g/cm³) and relatively high ranging from 85.6 to 56.8, which were obtained by sacrificial template method using polymethyl methacrylate spheres (PMMAs) of varying average particle sizes, from 9 to 34 μm, as sacrificial materials. A high refractive index ranging between 7.5 and 8.9 and a low absorption coefficient of approximately 17 cm⁻¹ at 0.3 THz were obtained for the porous ceramics with different total porosities derived from PMMAs with average particle sizes of 9 and 19 μm. Furthermore, effective medium and Mie scattering theories were applied to understand the effects of porous structure on the dielectric properties in microwave and terahertz frequency ranges, respectively, owing to the different wavelengths in the BSNBT matrix. The results of this study suggest that introducing a porous structure can effectively exploit lightweight microwave dielectric ceramic materials and provide valuable information on their terahertz response mechanism.     

ZnO-activated formation of phase pure perovskite Pb(In1/2Nb1/2)O3-Pb(Zn1/3Nb2/3)O3-PbTiO3 powder

This paper reports on the phase formation of perovskite Pb(In_1/2Nb_1/2)O₃-Pb(Zn_1/3Nb_2/3)O₃-PbTiO₃ (PIN-PZN-PT) powder when doped with 0.04 to 0.83 mol% ZnO. Air calcination of undoped powder mixtures for 4 hours at 800°C resulted in a mixture of Pb₂Zn_0.29Nb_1.71O_6.565 pyrochlore, PIN-PZN-PT perovskite, and In₂O₃. ZnO dopant concentrations as low as 0.04 mol% increased the rate of perovskite formation and resulted in near phase pure perovskite powder of 0.5 μm particle size when heated at 800°C in air. In all cases PbTiO₃ and Pb(In_1/2Nb_1/2)O₃ formed prior to PIN-PZN-PT formation. ZnO doping promotes perovskite phase formation by increasing the reactivity of the intermediate pyrochlore phase by substituting Zn²⁺ on Nb⁵⁺ sites and forming oxygen vacancies when heated in air. Heating in high resulted in an incomplete reaction and a mixture of perovskite and pyrochlore whereas low resulted in phase separation into a mixture of rhombohedral perovskite, tetragonal perovskite, and pyrochlore. The sensitivity clearly shows that oxygen vacancies due to ZnO-doping are critical for synthesis of phase pure PIN-PZN-PT powder.