High Temperature Operation Research Articles

Identification of diffusion interlayers of dissimilar welds under static tension by acoustic emission method

The paper studies the possibility of carbide and decarburized ferrite interlayers detection formed during the production and operation of dissimilar welded joints of austenitic to pearlitic steels. Diffusion interlayers may be interpreted as welded joint microstructure defects, since their formation can cause premature failure of the product under high-temperature operation conditions. In addition, with a certain chemical and structural-phase composition of the welded metals, brittle interlayers formation and development of cracks in the weld zone may be occurred. To identify diffusion interlayers, the acoustic emission (AE) method is used in this research. Specimens cut from welded joints were tested by tension until rupture with simultaneous recording of AE signals. Based on the research results, particular AE data signatures corresponding to the specimens with diffusion interlayers were identified. The main feature indicating the presence of diffusion interlayers is an increase in the amplitudes of AE impulses and AE activity at a stress value of 300 MPa, corresponding to the ultimate strength of the ferrite phase.

Glass-based encapsulant enabling SiC power devices to long-term operate at 300 °C

The high-temperature applications of Silicon Carbide (SiC) power devices are constrained by traditional epoxy molding compound (EMC). A significant challenge arises from the mismatch between the thermal expansion coefficients (CTE) of the encapsulant and the SiC chip, generating thermal and mechanical stresses during prolonged high-temperature operation. While glass encapsulants offer stability above 300 °C, these stresses can lead to mechanical degradation and eventual failure of SiC power devices. We design a glass-based encapsulation material to adjust the CTE of the glass to match that of the SiC chip (3–9 ppm/℃), enabling encapsulation of the device for long-term operation at 300 °C. Finite element analysis (FEA) confirms that the CTE adjustment effectively reducs internal thermal stresses. The glass composite with 10 wt% PbTiO3demonstrates a Tg of 310 °C and a CTE of 8.48 ppm/℃, successfully encapsulating a SiC schottky barrier diode in TO-247 package form. The encapsulated device exhibits low leakage current, a reverse breakdown voltage of 1,700 V, and a thermal resistance of 0.45 °C/W. Notably, the device maintains excellent performance even after 1,176 h of high-temperature aging, including 336 h at 300 °C and exhibits minimal change during thermal cycling between −50 and 150 °C for 100 cycles. Long-term performance analysis demonstrates superior stability compared to EMC encapsulation. These results highlight the potential of glass-based encapsulants for wide band gap power devices, offering reliability and performance under extreme conditions.

Chemical spray pyrolysis deposited ZnO/ZIF-8 and cobalt doped ZnO/ZIF-8 composite thin films for highly sensitive and selective ammonia sensing at room temperature

ZnO is a widely studied metal oxide for gas sensor applications concerning its biocompatibility and physio-chemical properties. However, the high operating temperature and low response are drawbacks. ZIF-8, the metal-organic framework of Zinc and imidazolate, is renowned for its gas adsorption property. The poor stability of ZIF-8 also limits its application as an effective gas sensor. Thus, a composite thin film of ZnO and ZIF-8 is deposited on a glass substrate using the chemical spray pyrolysis technique to detect ammonia at room temperature (300 K). The composite thin film is stable, has a good response, and is repeatable. Further, to enhance the sensor response at room temperature, Co is doped to the ZnO/ZIF-8 composite thin films. The sensor response for 1 ppm of ammonia for the Co doped ZnO/ZIF-8 is 301 at room temperature. Along with the gas adsorption capability of ZIF-8 providing more active sites, the change in morphology from flakes to spherical grains on doping with Co provided higher active surface area and free electrons and all together instigated fast redox reaction and conduction mechanism in ZnO. Hence, the Co doped ZnO/ZIF-8 composite thin films have an enhanced response of 117,285 to 50 ppm of ammonia.

Nanofibrous Covalent Organic Frameworks as the Cathode, Separator, and Anode for Batteries with High Energy Density and Ultrafast-Charging Performance.

To meet the demand for longer driving ranges and shorter charging times of power equipment in electric vehicles, engineering fast-charging batteries with exceptional capacity and extended lifespan is highly desired. In this work, we have developed a stable ultrafast-charging and high-energy-density all-nanofibrous covalent organic framework (COF) battery (ANCB) by designing a series of imine-based nanofibrous COFs for the cathode, separator, and anode by Schiff-base reactions. Hierarchical porous structures enabled by nanofibrous COFs were constructed for enhanced kinetics. Rational chemical structures have been designed for the cathode, separator, and anode materials, respectively. A nanofibrous COF (AA-COF) with bipolarization active sites and a wider layer spacing has been designed using a triphenylamine group for the cathode to achieve high voltage limits with fast mass transport. For the anode, a nanofibrous COF (TT-COF) with abundant polar groups, active sites, and homogenized Li+ flux based on imine, triazine, and benzene has been synthesized to ensure stable fast-charging performance. As for the separator, a COF-based electrospun polyacrylonitrile (PAN) composite nanofibrous separator (BB-COF/PAN) with hierarchical pores and high-temperature stability has been prepared to take up more electrolyte, promote mass transport, and enable as high-temperature operation as possible. The as-assembled ANCB delivers a high energy density of 517 Wh kg-1, a high power density of 9771 W kg-1 with only 56 s of ultrafast-charging time, and high-temperature operational potential, accompanied by a 0.56% capacity fading rate per cycle at 5 A g-1 and 100 °C. This ANCB features an ultralong lifespan and distinguished ultrafast-charging performance, making it a promising candidate for powering equipment in electric vehicles.

In the LiCl-KCl melt at 500<sup>о</sup>С depending on the content of Li<sub>2</sub>О и LiOH

Molten alkali metal chlorides used in pyrotechnologies are aggressive corrosive agents. The high operating temperature of the process, the heterogeneity of the environment, and the significant corrosion activity of the molten salt necessitate both the search for stable structural materials and the development of methods for protecting the structural elements of high-temperature technological devices. Corrosion loss reduction techniques traditionally used in low temperature environments are not applicable at high temperatures. The article examines the influence of oxygen-containing impurities (lithium oxide and hydroxide) on the corrosion behavior of metallic nickel (grade NP1) – the main component of candidate structural alloys, a thermodynamically and structurally stable material in the melt for the process of electrolytic refining of spent nuclear fuel. A method for preparing the LiCl–KCl salt electrolyte and obtaining lithium oxide by thermal decomposition of anhydrous lithium hydroxide under vacuum is described, and the concentrations of impurities in the electrolyte and the synthesized lithium oxide are determined. An installation for conducting corrosion tests in an inert atmosphere of a glove box is presented. To assess the corrosion resistance of the material, the following were used: gravimetric analysis, X-ray diffraction analysis of the surface and cross-sectional sections, and X-ray diffraction analysis of the surface of the samples. The dependences of the corrosion rate of the material on the concentration of oxygen-containing additives Li2O and LiOH were obtained. Based on a combination of gravimetric, X-ray microspectral and X-ray phase analysis data, it was established that metallic nickel samples demonstrate high corrosion resistance in the studied melts with the introduction of Li2O and LiOH additives.

A tutorial review on solid oxide fuel cells: fundamentals, materials, and applications

AbstractSolid oxide fuel cells (SOFCs) are recognized as a clean energy source that, unlike internal combustion engines, produces no CO2 during operation when H2 is used as a fuel. They use a highly efficient chemical-to-electrical energy conversion process to convert oxygen and hydrogen into electricity and water. They can provide smaller-scale power for transportation (e.g., cars, buses, and ships) and be scaled up to provide long-term energy for an electrical grid, making SOFCs a promising, clean alternative to hydrocarbon combustion. Conventional SOFCs faced challenges of high operating temperatures, high cost, and poor durability. Research into advanced cathode, anode, electrolyte, and interconnect materials is providing more insight into the ideal structural and chemical properties that enable the commercialization of highly stable and efficient intermediate temperature (IT) SOFCs. In this paper, we discuss the functional properties of the cathode, anode, electrolyte, and interconnectors for IT-SOFCs. The performance of SOFCs depends not only on the materials used but also on the optimization of operating conditions to maximize efficiency. The voltaic, thermodynamic, and fuel efficiency of SOFCs is presented.

Recent Advances in Barium Cobaltite-Based Perovskite Oxides as Cathodes for Intermediate-Temperature Solid Oxide Fuel Cells.

Solid oxide fuel cells (SOFCs) are considered as advanced energy conversion technologies due to the high efficiency, fuel flexibility, and all-solid structure. Nevertheless, their widespread applications are strongly hindered by the high operational temperatures, limited material selection choices, inferior long-term stability, and relatively high costs. Therefore, reducing operational temperatures of SOFCs to intermediate-temperature (IT, 500-800°C) range can remarkably promote the practical applications by enabling the use of low-cost materials and enhancing the cell stability. Nevertheless, the conventional cathodes for high-temperature SOFCs display inferior electrocatalytic activity for oxygen reduction reaction (ORR) at reduced temperatures. Barium cobaltite (BaCoO3-δ)-based perovskite oxides are regarded as promising cathodes for IT-SOFCs because of the high free lattice volume and large oxygen vacancy content. However, BaCoO3-δ-based perovskite oxides suffer from poor structural stability, inferior thermal compatibility, and insufficient ionic conductivity. Herein, an in-time review about the recent advances in BaCoO3-δ-based cathodes for IT-SOFCs is presented by emphasizing the material design strategies including functional/selectively doping, deficiency control, and (nano)composite construction to enhance the ORR activity/durability and thermal compatibility. Finally, the currently existed challenges and future research trends are presented. This review will provide valuable insights for the development of BaCoO3-δ-based electrocatalysts for various energy conversion/storage technologies.

Chemiresistive triethylamine detection based on the novel Ti3C2Tx/Co-BDC gas sensor

Triethylamine (TEA), a representative volatile organic environmental pollutant, poses significant environmental pollution risks and can adversely affect the liver and nervous system, potentially leading to fatal outcomes. However, existing gas sensors for TEA detection have pressing drawbacks, such as safety hazards associated with high-temperature operation and poor timeliness due to time-consuming testing. Herein, the Ti3C2Tx/Co-BDC sensor demonstrates ultra-sensitive detection of TEA at a low temperature of 100 °C. This temperature is below the threshold for explosion-proof operation, ensuring safe application in flammable and explosive environments. Meanwhile, the introduction of the metal-like MXene with ultra-high conductivity accelerates the response and recovery process (11 s/20 s), facilitating highly efficient TEA detection within a sub-minute timeframe. The Ti-O-Co interfacial bonds between Ti3C2Tx and Co-BDC, confirmed by both XPS analysis and theoretical calculations, enhance carrier mobility across the two materials, significantly boosting gas-sensing performance. The rapid detection of TEA at low temperatures makes the Ti3C2Tx/Co-BDC sensor more suitable for practical environmental monitoring in flammable and explosive areas, further contributing to human health and production safety.

Multiscale textured solar absorber coatings for next-generation concentrating solar power

A high-temperature stable solar absorber is crucial for next-generation (Gen3) concentrating solar power (CSP) plants, to enable high temperature operation, maximize power generation efficiency, and thereby reduce the levelized cost of energy. This study presents novel, fractal-textured solar absorber coatings whose multiscale feature scales effectively match the visible region of the solar spectrum, leading to superb absorptive properties. Single and bimetallic oxide coatings of copper, cobalt and manganese were prepared on Inconel 625 substrates using electrodeposition. The effect of electrodeposition parameters and annealing temperature are systematically studied to optimize the morphology and properties of the oxide coatings. Multiscale textured bimetallic coatings of copper manganese oxide and copper cobalt oxide demonstrate a superior absorptance of 0.985, a remarkably low emittance <0.45 and an exceptional optical efficiency of ∼96 % under Gen3 CSP operating conditions, surpassing previously reported values in the literature by about 5 %. Durability tests confirmed the coatings’ steadfast endurance of mechanical and environmental stress, making them suitable for long-term application in harsh CSP environments.

The influence of the elemental valence on the thermophysical properties of high entropy (La0.2Sm0.2Eu0.2Yb0.2Y0.2)2(Ce0.5Zr0.5)2O7 coatings for thermal barrier application

Commercial yttria-stabilized zirconia (YSZ) thermal barrier coatings (TBCs) are no longer sufficient for the stringent demands in the high operating temperature and excellent thermophysical properties of the high-performance gas turbines and aviation engines. High entropy ceramics, distinguished by their superior thermophysical properties, have risen as a potential substitute for TBCs. However, the realm of atmospheric plasma spraying (APS) in the creation of these advanced TBCs remains relatively unexplored. In this work, three distinct high-entropy (La0.2Sm0.2Eu0.2Yb0.2Y0.2)2(Ce0.5Zr0.5)2O7 coatings were developed through the meticulous alteration of spraying power. The effects of spraying power on the microstructure, valence states of constituent elements and thermophysical properties of the coatings were deeply investigated. The results indicated that all the as-sprayed coatings exhibit a defect fluorite structure. Spraying power does have a significant impact on the thermophysical properties of the coatings. With the decrease in spraying power, the thermal conductivity of the coatings shows a progressive reduction, whereas the coefficient of thermal expansion (CTE) exhibits a gradual increase. This trend is closely related to valence states of constituent elements in the coatings. The resulting coating exhibits a low thermal conductivity of 0.54 W⋅m-1⋅K-1, a high CTE of 11.22×10-6·K-1 and a superior phase stability at elevated temperatures.

Facile synthesis of silver and copper modified graphitic carbon nitride for volatile organic compounds sensing

Volatile organic compounds (VOCs) pose significant health risks when inhaled or ingested in large quantities. Metal oxide-based solid-state gas sensors are commonly utilized for VOCs detection, including methanol, however their high operating temperature and selectivity are both biggest challenges. In this context, graphitic carbon nitride (g-C3N4) has emerged as a promising alternative for VOCs sensing due to its superior sensing properties. In this work, Cu and Ag doped g-C3N4 was synthesized via the polycondensation method for VOCs sensing applications. All the samples showed a selective response to methanol at room temperature. Notably, the Ag/g-C3N4 sensor exhibited a significantly enhanced response (~27.5) compared to both undoped g-C3N4 (~3.58) and Cu/g-C3N4 (~9.82) sensors towards 200 ppm methanol. The Ag/C3N4 based sensor showed rapid response (21 s) and recovery (17 s) times, along with excellent short-term and long-term stability. It was found that Ag/C3N4 sensor exhibited a good response to humidity levels ranging from 9 % to 93 % RH, without any significant variation observed when deposited on the ceramic and flexible polyimide substrates. Further, considering its practical applicability, the Ag/C3N4 sensor showed successful detection of alcohol in human breath, highlighting its potential for real-world applications.

Two‐Dimensional Solidification Simulation of PCM Molten Salt as a Thermal Energy Storage for Stirling Engine

ABSTRACTThermal energy storage technologies have been widely used to mitigate intermittency from renewable energy sources such as solar energy. Phase change material (PCM) is a material that can be used as a heat storage medium and is available in a wide range of operating temperatures. Molten salt is one of the PCMs that has the advantage of a very high operating temperature. The PCM solidification simulation based on HitecXL molten salt using COMSOL Multiphysics software was carried out with variations in heat absorption of 1–5 kW/m2, assuming constant heat absorption. The results showed that the PCM solidification process started from the surface of the Stirling engine heat exchanger pipe. The part of the PCM that is solidified falls due to gravity, causing a phenomenon similar to a droplet. The flow that occurred was natural, driven by the buoyancy force resulting from density changes due to temperature gradients in the solidification process. The time required for the PCM to completely solidify was closely related to the amount of heat absorption; the greater the heat absorption from the pipe, the faster the PCM is fully solidified.

Enhanced wear resistance, corrosion behavior, and thermal management in magnesium alloys with PEO coatings

The harsh conditions encountered in aerospace applications, such as high operational temperatures, abrasive wear, and corrosive substances, present significant challenges to the performance and longevity of magnesium alloy components. To create a coating with superior wear resistance, corrosion resistance, and high emissivity, this study employs plasma electrolytic oxidation (PEO) technology to develop a nanocomposite coating doped with carbon nanotubes (CNTs) and hexagonal boron nitride (h-BN). The results demonstrate that the MgO-BN/CNTs coating with an emissivity of 0.82 reduces the equilibrium temperature of the 5 W LED junction by nearly 10 °C compared to the magnesium alloy substrate, showing improved radiative heat dissipation performance. Due to the ability of the porous structure to accommodate abrasive particles, coupled with the lubricating effect of h-BN and CNTs, the friction coefficient of the MgO-BN/CNTs coating is 0.57, which is 21 % lower than that of the MgO coating. Additionally, the coating exhibits excellent corrosion protection, attributed to the dense microstructure and chemical inertness of h-BN. The findings demonstrate that the strategic incorporation of h-BN and CNTs into PEO coatings effectively improves the wear resistance, corrosion resistance, and thermal management performance of magnesium alloys.

Investigations of inlet arrangement strategies and particle parameters on thermochemical performance in falling particle solar reactors

The reformation of methane to hydrogen and steam in a falling particle solar reactor (FPSR) is a promising method to use the solar energy, which converts solar energy into chemical energy. FPSR has higher operation temperature, higher pressure bearing capacity and more direct heat energy storage than those of traditional reactor. However, due to the short residence time of the particles, hydrogen production efficiency is reduced. Thus, inlet arrangement strategies and particle catalysts should be carefully designed to improve the thermochemical reaction performance of FPSR. In this contribution, the Eulerian-Eulerian model in CFD program (Fluent 2020 R2) is used to explore the effects of different particle inlet arrangement strategies, non-uniform particle mass flow inlet and particle size on the performance enhancement of methane steam reforming reaction. The results indicate that the two arrangement strategies show different trends in influencing hydrogen production efficiency. Besides, non-uniform particle mass flow rate also has a significant impact on hydrogen production efficiency, with the optimal arrangement conditions increasing the hydrogen production rate by 2.4831 mol/m−3(−|-) s−1. Additionally, smaller particle size demonstrates better hydrogen production efficiency, with a 0.15 mm particle size catalyst showing a 14.02 % improvement in hydrogen production efficiency compared to a 0.75 mm particle size. This contribution can provide a guidance for optimizing the heat and mass transfer performance of the falling particle solar reactor.

Effect of High-Temperature Operation on Voltage Cycling Induced PEMFC Degradation: From Automotive Customer Drive Cycles to an Accelerated Stress Test

Degradation of the Pt catalyst during load cycling constitutes a major durability issue for proton exchange membrane fuel cells (PEMFCs) in automotive applications. In this study commercial 5 cm2 electrodes were exposed to 20 k voltage cycles between 0.6–0.9 VRHE at temperatures ranging from 75 to 120 °C. The electrochemical surface area (ECSA), the roughness factor (rf), and the oxygen transport resistance were investigated over the course of the test. The degradation was mainly governed by Pt agglomeration and was accelerated with increasing temperature. Interestingly, operation at high temperature (120 °C and 30% RH) caused the same ECSA loss as at standard conditions (90 °C and 90% RH), suggesting that when maintaining dry conditions high-temperature operation is not critical for the durability of the catalyst material. The experimental results were used to validate an existing 0D catalyst degradation model, which was then applied to an automotive customer drive cycle. The calculated degradation over the whole automotive lifetime (excluding startup shutdown and idle events) equals 20 k voltage cycles (0.6–0.9 V, 10 s hold time) at 90 °C and 30% RH, which provides a guideline for the assessment of the suitability of novel catalyst materials for automotive applications.

An open-loop and closed loop based passive thermal management techniques applicable to photovoltaic systems

Photovoltaic (PV) technology adoption in recent years has experienced significant growth due to its inherent advantages over alternative technologies. Nevertheless, there is a concern regarding performance deterioration due to high operating temperatures. Various thermal management methods have been studied to address this issue, each having its own advantages and disadvantages. Hence, a comprehensive review aimed at developing effective passive cooling techniques was undertaken and two techniques were finalized for outdoor testing viz. natural circulation loop based cooling (PV-NCL) and evaporative cooling (PV-EVP). Though the former version could drop module temperature by 7.4 °C–13.9 °C (Power output increment in the range of 3.5 %–6.7 %), this improvement was not sustained throughout the day due to factors such as flow resistance within the loop and a lack of convective cooling in the vicinity of the cooler. Subsequent experiments confirmed that loop resistance played a dominant role in this phenomenon. Additionally, concerns about water circulation in PV-NCL were resolved through a comparison with water duct-integrated PV. On the other hand, the innovative gravity-assisted water flow for evaporation method (PV-EVP) yielded more promising results, with a power output enhancement ranging from 3.7 % to 11.5 %. However, considering the in-field operational issues, PV-NCL with a modified design will likely be the best technique.

Reducing dislocations for room-temperature continuous-wave InGaAs/AlGaAs multiple quantum well lasers monolithically grown on Si

As dislocation-sensitive light-emitting devices, quantum well lasers monolithically grown on Si substrates operate poorly compared to their counterparts on native ones. In this work, a GaAs/Si virtual substrate with a low threading dislocation density of 8.9×106/cm2 was achieved by using a combined dislocation-reducing method. Meanwhile, by using two In-containing strained layer separately inserted into upper and lower AlGaAs cladding layers, the active region was virtually free of gliding dislocations. With the reduced dislocations in the active region, the fabricated Si-based broad-stripe ridged lasers exhibited continuous-wave lasing at room temperature, and a low threshold current density of 1015 A/cm2, high operation temperature of 90°C as well as a device lifetime of over 87.25 h were achieved. These results demonstrate an experimentally feasible way to optimize a Si-based InGaAs/AlGaAs quantum well laser and further promote the research on monolithic integration.

Analysis of the influence of expansion gap on thermal stress and strain distribution of a hot blast stove

The hot blast stove is an important facility in the steel industry, which of the expansion gaps design has a significant buffering effect on the thermal stress with a high-temperature operating process. In this paper, a 3D numerical model of a hot blast stove was established to calculate the thermal stress distribution and analyze the remaining thickness of expansion gaps with different parts during the operating process. Young’s Modulus of the refractory linings was obtained by comparing with the experiment data and numerical data under the different temperatures and considering the influence of mortar. The result shows that Young’s Modulus of the refractory brick increased as the temperature, and the comparison of the experiment and simulation data of Young’s Modulus under three different temperatures displayed good agreement between the two sets of data. The first/third principle stress for the refractory linings can be reduced effectively by designing the expansion gap rationally, and the equivalent stresses of the shell are mainly concentrated at the joint and the neck. In addition, the expansion gaps are decreased under the thermal expansion and moved along a radial direction for the combustion/checker dome and the combustion/checker chamber.

Low-Power Chemiresistive Gas Sensors for Transformer Fault Diagnosis.

Dissolved gas analysis (DGA) is considered to be the most convenient and effective approach for transformer fault diagnosis. Due to their excellent performance and development potential, chemiresistive gas sensors are anticipated to supersede the traditional gas chromatography analysis in the dissolved gas analysis of transformers. However, their high operating temperature and high power consumption restrict their deployment in battery-powered devices. This review examines the underlying principles of chemiresistive gas sensors. It comprehensively summarizes recent advances in low-power gas sensors for the detection of dissolved fault characteristic gases (H2, C2H2, CH4, C2H6, C2H4, CO, and CO2). Emphasis is placed on the synthesis methods of sensitive materials and their properties. The investigations have yielded substantial experimental data, indicating that adjusting the particle size and morphology structure of the sensitive materials and combining them with noble metal doping are the principal methods for enhancing the sensitivity performance and reducing the power consumption of chemiresistive gas sensors. Additionally, strategies to overcome the significant challenge of cross-sensitivity encountered in applications are provided. Finally, the future development direction of chemiresistive gas sensors for DGA is envisioned, offering guidance for developing and applying novel gas-sensitive sensors in transformer fault diagnosis.

Enhancing piezoelectric properties of BiScO3-PbTiO3 ceramics via- incorporation of Bi(Zn1/2Ti1/2)O3 with high spontaneous polarization

High-performance piezoelectric materials are the core elements for the fabrication piezoelectric transducers and actuators. In recent years, there has been an increasing demand for piezoelectric materials with both high operational temperature and large piezoelectricity. However, the conventional approach of soft doping to enhance the piezoelectric response often results in a reduction in Curie temperature. To address this issue, we incorporated Bi(Zn1/2Ti1/2)O3 with a large spontaneous polarization (Ps ∼ 100 µC/cm2) and high Curie temperature (Tc ∼ 1380 °C) into BiScO3-PbTiO3 ceramics to improve the piezoelectric response while maintaining high Tc. The newly developed 0.08Bi(Zn1/2Ti1/2)O3-0.335BiScO3-0.585PbTiO3 ceramic exhibits impressive properties including a high d33 value of 585 pC/N (increased by ∼ 33 % compared to the 0.36BiScO3-0.64PbTiO3 ceramics), an electromechanical coupling coefficient k33 of 0.75, a dielectric constant ε′ of 2380, a relatively high Tc of 421 °C. These remarkable improvements hold great promise for advancing high-temperature piezoelectric devices.