Temperature Coefficient Research Articles

Mechanical Structure Design of Pressure Sensors with Temperature Self-compensation for Invasive Blood Pressure Monitoring

Abstract Invasive blood pressure (IBP) is a fundamental part of basic cardiovascular monitoring. Conventional piezoresistive pressure sensors are limited in usage due to the high cost associated with equipment and intricate fabrication processes. Meanwhile, low-cost strain gauge pressure sensors have poor performance in the gauge factor (GF) and temperature insensitivity. Here, we report a mechanical structure design for diaphragm pressure sensors (DPSs) by introducing a compensation grid to overcome the aforementioned challenges. A simplified model is established to analyze the mechanical deformation and obtain the optimal design parameters of the DPS. By rationally arranging the placement of sensitive grids to eliminate the discrepancy of relative resistance changes within four arms of the Wheatstone full-bridge circuit, the appropriate GF and high temperature insensitivity are simultaneously achieved. The blood pressure sensor with the DPS is then fabricated and characterized experimentally, which demonstrates an appropriate GF (ΔU/U0)/P = 3.56 × 10−5 kPa−1 and low temperature coefficient of voltage (ΔU/U0)/ΔT = 3.4 × 10−7 °C−1. The developed mechanical structure design offers valuable insights for other resistive pressure sensors to improve the GF and temperature insensitivity.

A 10 µH Inductance Standard in PCB Technology with Enhanced Protection against Magnetic Fields

Low-frequency working standards of inductance are generally uniformly wound toroids on a ceramic core. Planar inductors made using printed circuit board (PCB) technology are simple and cheap to manufacture in comparison to inductors wound on toroid cores, but they are significantly prone to the influence of external magnetic fields. In this paper, we propose the design of a PCB inductance working standard of 10 μH, consisting of a duplex system of planar PCB coils, electrostatic shielding, and an enclosure. Alongside an electromagnetic analysis and design procedure, the measurements on the manufactured prototype included the generated magnetic field, the thermal time constant of the enclosure, temperature coefficients, and its error analysis. The measurements show negligible generated magnetic fields (<1.68 nT at 7 cm, 49 mA, 10 kHz). The minimum thermal time constant of the enclosure is 1270 s and the temperature coefficient of resistance is 0.00384 1/℃. The presented method of temperature coefficient measurement using a climate chamber allows for measurements in the temperature range of 10 °C to 40 °C. In this temperature range, the results show an inductance variation of 0.05 µH at 50 kHz, while the uncertainty of inductance measurement at this frequency was 0.03 µH (k = 2).

Investigating the electrical and thermal properties of Cu and Al-doped ZnO thick films using the screen-printing technique for thermal resistance applications

The important properties of prepared Zinc Oxide (ZnO) thick films were investigated. The electrical and thermal properties of ZnO thick films were measured and analyzed using the MATLAB simulation tool. On a glass substrate, thick films of pure ZnO as well as ZnO doped with Cu and Al materials were fabricated using the screen-printing technique. The electrical parameters were calculated using the half-bridge approach to determine the unknown resistance, change in current, and voltage. The half-bridge circuit having a 50 M Ω reference resistance with 30 V excitation voltage. The thermocouple transducer (K type) was used to measure the heating and cooling temperature between 40 °C to 370 °C. The measured maximum TCR values are 0.0095 ppm/°C for pure ZnO film, 0.0068 ppm/°C for Cu-doped ZnO film, and 0.0123 ppm/°C for Al-doped ZnO film. The maximum measured resistance values are 5.9 × 107 Ω for pure ZnO film, 5.9 × 107 Ω for Cu-doped ZnO film, and 5.9 × 107 Ω for Al-doped ZnO film. Using MATLAB simulation, it was possible to observe key factors including the activation energy, unknown resistance, IV characteristics, thermal properties, temperature coefficient resistance (TCR) and resistive linear behavior of the ZnO films.

Microwave properties of SrY2O4 spinel synthesized for advanced applications

This study investigated the microwave dielectric properties and microstructures of SrY2O4 ceramics fabricated using the conventional solid-state route. The investigation revealed that the dielectric constant (ε r ) values exhibited saturation behavior, reaching a plateau within the range of 14–15. Notably, high quality factor (Q⋅f) values ranging from 64,500 to 92,000 (measured at 11 GHz) were achievable when sintering temperatures were maintained between 1480 and 1520 °C. Furthermore, the temperature coefficient of resonant frequency (τ f ) demonstrated minimal sensitivity to variations in sintering temperature. Significantly, SrY2O4 ceramics sintered at 1520 °C for 4 h exhibited a desirable combination of microwave dielectric properties, including a high ε r value of 15, an exceptional Q⋅f value of 92,000, and a favorable τ f value of −6.2 ppm/°C. These findings suggest the potential of SrY2O4 ceramics, particularly under these specific sintering conditions, for applications in microwave devices.

Thermodynamic properties of hercynite (FeAl2O4) for thermochemical water splitting applications: A first-principles approach

FeAl2O4 is considered as a potential material to produce solar thermochemical hydrogen. However, its temperature and pressure dependant thermodynamic properties have not yet been well explored. In this work, first-principles calculations have been applied to investigate the structural, mechanical, electronic and thermodynamic properties of FeAl2O4. The temperature and pressure-dependent thermal expansion coefficient and Grüneisen parameter have been calculated, leading to the calculation of molar heat capacity, cp = 5.50907 + 0.39378 T-202345.44153 T-2-94039T2 at 0 GPa. Change in Gibb's energy can be calculated at a given temperature and pressure during the reduction and oxidation cycle to computationally assess the suitability of FeAl2O4, as a catalyst for thermochemical water splitting. This approach may be further extended using suitable substitution and subsequent compositional variation of Fe and Al atoms, to explore more efficient catalyst.

Effects of rotational speed of the classifying wheel during jet milling on magnetic properties and thermal stability of sintered Nd-Fe-B magnets

Sintered Nd-Fe-B magnets with different grain sizes are prepared by adjusting rotational speed of the classifying wheel during the jet milling process. The microstructures of the magnets, the element contents of the magnets, the relationship between powder particle size and grain size and the magnetic properties of the magnets are studied by X-ray diffracton (XRD), scanning electron microscopy (SEM), optical microscopy (OM), electron backscattered diffraction (EBSD), inductively coupled plasma (ICP) and permanent magnet tester. The effect of grain size on thermal stability is characterized by the temperature coefficient of coercivity from room temperature to working temperature and the irreversible magnetic flux loss of the magnet at high temperature. The results show that the particle size of the alloy powder decreases with the increase of the rotational speed of the classifying wheel. When the alloy powder is formed and sintered, it is found that the grain size of the prepared magnet decreases with the decrease of the particle size of the alloy powder. The finer the grain size of the magnet, the clearer the grain boundary. As the grain size of the magnet decreases, the coercivity of the magnet increases, the remanence of the magnet decreases slowly and the thermal stability of the magnet becomes better. For the magnet with a rotational speed of the classifying wheel of 4900 r/min, the average grain size of the magnet is 4.70 μm, the coercivity (Hcj) is 15.47 kOe, and the remanence (Br) is14.09 kGs. At a temperature of 80 °C, the coercivity temperature coefficient of the magnet reaches −0.745 %/°C, and the irreversible loss of magnetic flux hirr is 16.49 %. In addition, the magnet prepared by the tail material produced a large number of voids and pores due to the high oxygen content. Tail material is not good enough in terms of magnetic property as well as thermal stability.

Role of (Pr20Nd80)60Tb15Cu15Ga10 intergranular addition on the magnetic properties of Nd-Fe-B sintered magnet

Intergranular addition using heavy rare earth (HRE) Dy/Tb containing alloys has been an effective way to modulate the microstructure and chemical distribution towards fabricating high-coercivity Nd-Fe-B sintered magnets. In this work, (Pr20Nd80)60Tb15Cu15Ga10 (at%) intergranular alloy powders were designed and introduced with dual purposes of forming Tb-rich matrix shell and antiferromagnetic RE6Fe13Ga grain boundary phase (GBP). With 3 wt% (Pr20Nd80)60Tb15Cu15Ga10 addition, the coercivity Hcj is significantly increased from 11.1 kOe to 17.9 kOe, accompanied with a high utilization efficiency of Tb (11.8 kOe/%) and a superior temperature coefficient of coercivity β(−0.531%/K). Microstructural analysis suggests that the improved wettability of grain boundary by (Pr20Nd80)60Tb15Cu15Ga10 addition is beneficial to form the Tb-rich matrix shell and antiferromagnetic RE6Fe13Ga GBP throughout the bulk magnets. Micromagnetic simulation is implemented to study the effect of formed ferromagnetic/antiferromagnetic GBP and Tb-rich matrix shell on the magnetization reversal process. Results show that the synergy of Tb-rich shell surrounding Nd/Pr-rich core and antiferromagnetic Nd/Pr-rich RE6Fe13Ga GBP is an effective way to promote the coercivity with high utilization efficiency of HRE Tb.

Multilateral evaluation of the effects of utilizing thorium oxide in the Bushehr VVER-1000 reactor

Abstract The use of thorium oxide in thermal reactors is currently being explored due to its promising outcomes. One primary concern is how to reduce the pollution of core components and nuclear waste. The inclusion of 232Th in the reactor leads to the production of 233U and decreases the formation of minor actinides. On the other hand, 238U increases the production of 239Pu, a toxic and strategically significant isotope, along with minor actinides. Therefore, the potential of thorium to reduce the production of 239Pu, one of the most harmful isotopes, can be assessed in the Bushehr VVER-1000 reactor. This study involved replacing some uranium in the Bushehr VVER-1000 reactor with 232Th. The research focused on examining the environmental impact of nuclear waste, including activity, chain reactions, and isotope levels, over a two-year period. The impact of the new fuel substitution was evaluated in the Bushehr reactor, which has a power of 3,000 MWth, in three scenarios: thorium addition to 1.6 % enriched assemblies, thorium addition to 2.4 % enriched assemblies, and thorium addition to 3.6 % enriched assemblies. These changes were analyzed in terms of nuclear waste contamination, plutonium production, fuel burn-up, and conversion ratio, and compared to the reactor using UO2 fuel. The simulation was conducted using the MCNPX 2.6.0 computational code and heterogeneous geometry. The results indicate that nuclear waste pollution decreased when thorium was added to the 1.6 % and 2.4 % enriched assemblies, but increased when added to the 3.6 % assemblies. Additionally, fuel burn-up increased with the addition of thorium in the 1.6 % and 2.4 % assemblies, but decreased in the 3.6 % assemblies. However, the conversion ratio increased in all cases. The fuel temperature coefficient (FTC), moderator temperature coefficient (MTC), and void coefficient (VC) were calculated and evaluated.

A 3.0-V 4.2-μA 2.23-ppm/°C BGR with cross-connected NPNs and base-current compensation

This paper presents a high-precision, low-power bandgap voltage reference with a 3.0 V output voltage suitable for battery-management systems. Compared to Brokaw's type bandgap references (BGRs), Cross-connected NPN transistors facilitate higher output voltages without the necessity of operational amplifiers and are unaffected by the current-mirror mismatch. Base-current compensation is proposed to address the effect of base current on voltage output temperature characteristics at low power consumption. A piecewise exponential curvature correction stains high-order compensation for the nonlinear characteristic of base-emitter voltage. Experimental results of the proposed BGR implemented in a 0.18-μm Bipolar-CMOS-DMOS (BCD) process demonstrate that the temperature coefficient is 2.23 ppm/°C over the range of −40 °C–120 °C. The line regulation is 0.2 mV/V at a 5–6 V supply voltage with a supply current of only 4.2 μA. The die area of the fabricated BGR is 0.105 mm2.

Enhanced dielectric and electrical properties of Ba(1−x)Nd2x∕3Zr0.1Ti0.9O3 (0.00 ≤ x ≤ 0.04) electroceramics for high temperature-based energy storage devices

The demand for high-temperature endurable dielectric materials with higher thermal stability in electronic systems operating under extreme temperatures sets a significant channel for the electronic industry. This work focuses on the dielectric and impedance behavior for lead-free Ba1−xNd2x∕3Zr0.1Ti0.9O3 (BNZT); (0.00 ≤x≤ 0.04) between 300 ∘C – 400 ∘C and synthesized by conventional solid-state reaction method at optimum temperatures. Structural characterizations confirmed the tetragonal (P4mm symmetry) structure formations for the BNZT ceramics. XPS analysis confirmed the Nd-substitution at the Ba-site in the BNZT ceramics. FE-SEM study showed grain growth reduction with enhanced grain boundaries. The dielectric study showed lower dielectric loss with enhanced dielectric permittivity at high temperatures. Impedance analysis confirmed the negative temperature coefficient of resistance (NTCR) and non-Debye type behavior with higher thermal stability. Singly-ionized oxygen vacancies mainly govern the conduction process in BNZT ceramics. Enhanced dielectric and impedance properties suggest that Nd-substituted BNZT electroceramics are promising materials for applications in high-temperature-based energy storage systems.

Optimizing microwave dielectric properties of low‐temperature sintered Sr/Zn‐substituted BaMg2V2O8 by mixing with TiO2

AbstractBa1 − xSrxMg2 − yZnyV2O8 compounds, abbreviated as BSMZVO@xy (x = 0.0–0.2 and y = 0.02), were synthesized with tetragonal structures. The microstructure, molecular structure, and polarization mechanism were investigated using X‐ray diffraction, electronic microscopy, Raman spectroscopy, and vector network analyzer. The sintering temperatures (<900°C) and microwave dielectric properties of BSMZVO are significantly impacted by (Sr/Zn)2+ substitution and TiO2 mixing. The BSMZVO@xy (x = 0.15 and y = 0.02) exhibited encouraging εr (12.4–12.7), Q × f (40 054–40 973 GHz), and temperature coefficient of resonance frequency (τf ∼ −5.2 to 0.0 ppm/°C) after sintering at 860°C/4 h and 800°C/4 h. For the first time, TiO2 was added to enhance the density and Q × f value without degrading τf. The 0.25 wt.% TiO2 resulted in optimum εr of 13.4, Q × f of 43 636 GHz, and τf of +1.8 ppm/°C after sintering at 760°C/4 h. The improved quality factor (Q × f) is linked to the Raman A1g mode and relative density.

Preparation of Ultra-Sensitive flexible temperature sensors with thermal responsive waterborne polyurethane for enhanced temperature sensing performance

Flexible temperature sensors with superior resolution and reliable repeatability are crucial in the burgeoning field of electronic skins (e-skins). In this study, we synthesized thermo-responsive materials with mechanical flexibility by incorporating multi-wall carbon nanotubes (MWCNT) into waterborne polyurethane (WPU) matrix via covalent bonding. The thermal movement of WPU chain segments serves as the driving force, endowing the resultant material with excellent temperature response properties and stability. The MWCNT@WPU sensor demonstrates ultra-high sensitivity (−5.63 % K−1), high accuracy (0.1 °C), rapid response (mere 4.5 s), and long-term durability (up to 30 days) for temperature sensing within the range of 30 to 60 °C. Importantly, the temperature coefficient of resistance (TCR) can be tailored by adjusting the molecular weight of WPU soft segments and the ratio of hard segment to soft segment in WPU. Moreover, the developed sensor exhibits outstanding detection accuracy and stability in practical applications such as continuous water temperature monitoring, breathing rate measurement, and human skin temperature sensing, highlighting its immense potential in the e-skins field, catering to applications in healthcare monitoring, intelligent robotic platforms, and environmental surveillance.

Alumina fiber/reduced graphene oxide composite films for high-temperature heating and sensing

Reduced graphene oxide (rGO) and its composite films have aroused intense interest in electrical heating and temperature sensing fields, but the working temperature is usually limited because the internal layer-stacked structure is breakable at high temperature. In order to promote structure stability, a series of Al2O3 fiber/rGO composite films were developed. It is found that gaseous products mainly including CO2 and CO during thermal reduction contribute to pores, bulges and intervals in rGO films, while appropriate Al2O3 fiber has an adhesion effect on rGO sheets and tightens them together, in which case defects can hardly form and the layered structure is significantly compacted. Therefore, the degree of stacking order and tensile strength tend to increase, resulting in the improvement of structure stability and decrease of electrical resistivity. However, excess Al2O3 fiber makes the formation of debris and cracks, causing the deterioration of conductivity and mechanical properties. With 20 wt% Al2O3 fiber, the composite films can bear higher heating voltage than pure rGO films and stabilize at 634.65 °C under 36 V, which also keep a good linearity between resistance and temperature from 25 to 600 °C, exhibiting a considerable temperature coefficient of resistance (TCR) with −1.70×10−3 /°C at room temperature.

Sensitivity enhancement of thermal acoustic particle velocity sensor based on metal film optimization

Thermal acoustic particle velocity sensors find widespread application in sound field measurements and sound source localization, owing to their capacity to capture vectorial information. This paper focuses on enhancing the sensitivity of detecting weaker signals by elevating the temperature coefficient of resistance (TCR) in the platinum thin film on the sensor's sensing wires. The study delves into the impact of annealing on the TCR of Pt thin films applied to small-sized elongated wires for thermal acoustic particle velocity sensors. The augmented effects of annealing Pt thin films with three adhesion layer metals—Chromium (Cr) and Titanium (Ti), previously commonplace in this sensor, and the newly introduced Tantalum (Ta) are scrutinized. Additionally, the influence of the deposition of Au electrodes, employed for wire bonding, both before and after annealing, on the annealing effect is also explored. In conclusion, a Pt thin film annealing process tailored for thermal acoustic particle velocity sensors is proposed, along with the recommendation of the optimal adhesion layer metal. This approach results in a substantial 20 % improvement in the TCR of the Pt thin film on the sensing wires, coupled with a corresponding 2.2 dB increase in sensor sensitivity.

Entropy Engineering toward Positive Temperature Coefficient and Large Voltage in High-Temperature Zinc-Ion Batteries

Entropy Engineering toward Positive Temperature Coefficient and Large Voltage in High-Temperature Zinc-Ion Batteries

Small-size temperature/high-pressure integrated sensor via flip-chip method

Hydraulic technology with smaller sizes and higher reliability trends, including fault prediction and intelligent control, requires high-performance temperature and pressure-integrated sensors. Current designs rely on planar wafer- or chip-level integration, which is limited by pressure range, chip size, and low reliability. We propose a small-size temperature/high-pressure integrated sensor via the flip-chip technique. The pressure and temperature units are arranged vertically, and the sensing signals of the two units are integrated into one plane through silicon vias and gold–gold bonding, reducing the lateral size and improving the efficiency of signal transmission. The flip-chip technique ensures a reliable electrical connection. A square diaphragm with rounded corners is designed and optimised with simulation to sense high pressure based on the piezoresistive effect. The temperature sensing unit with a thin-film platinum resistor measures temperature and provides back-end high-precision compensation, which will improve the precision of the pressure unit. The integrated chip is fabricated by MEMS technology and packaged to fabricate the extremely small integrated sensor. The integrated sensor is characterised, and the pressure sensor exhibits a sensitivity and sensitivity drift of 7.97 mV/MPa and −0.19% FS in the range of 0–20 MPa and −40 to 120 °C. The linearity, hysteresis, repeatability, accuracy, basic error, and zero-time drift are 0.16% FS, 0.04% FS, 0.06% FS, 0.18% FS, ±0.23% FS and 0.04% FS, respectively. The measurement error of the temperature sensor and temperature coefficient of resistance is less than ±1 °C and 3142.997 ppm/°C, respectively. The integrated sensor has broad applicability in fault diagnosis and safety monitoring of high-end equipment such as automobile detection, industrial equipment, and oil drilling platforms.

Validation of the SCALE/Polaris−PARCS Code Procedure with the ENDF/B-VII.1 AMPX 56-Group Library: Pressurized Water Reactor

This study was conducted to validate the SCALE/Polaris v6.3.0–PARCS v3.4.2 code procedure with the Evaluated Nuclear Data File (ENDF)/B-VII.1 AMPX 56-group library for pressurized water reactor (PWR) analysis, by comparing simulated results with measured data for critical experiments and operating PWRs. Uncertainties of the SCALE/Polaris–PARCS code procedure for PWR analysis were evaluated in the validation for the PWR key nuclear parameters such as critical boron concentrations, reactivity, control bank work, temperature coefficients, and pin and assembly power peaking factors.

Climate Change Threatens Barringtonia racemosa: Conservation Insights from a MaxEnt Model

Barringtonia racemosa (L.) Spreng. (Lecythidaceae), a crucial species in mangrove ecosystems, is facing endangerment primarily due to habitat loss. To address this issue, research is imperative to identify suitable conservation habitats for the endangered B. racemosa within mangrove ecosystems. The utilization of the optimized Maximum Entropy (MaxEnt) model has been instrumental in predicting potential suitable regions based on global distribution points and environmental variables under current and future climates conditions. The study revealed that the potential distribution area of B. racemosa closely aligns with its existing range with an Area Under the Curve (AUC) greater than 0.95. The Jackknife, AUC, percent contribution (PC), and permutation importance (PI) tests were employed alongside the optimized MaxEnt model to examine the influence of environmental variables on the distribution of B. racemosa. The primary factors identified as significant predictors of B. racemosa distribution included the average temperature of the ocean surface (Temperature), average salinity of the ocean surface (Salinity), precipitation of the warmest quarter (Bio18), precipitation of the driest month (Bio14), seasonal variation coefficient of temperature (Bio4), and isothermality (Bio3). Currently, the habitat range of B. racemosa is predominantly found in tropical and subtropical coastal regions near the equator. The total suitable habitat area measures 246.03 km2, with high, medium, low, and unsuitable areas covering 3.90 km2, 8.57 km2, 16.94 km2, and 216.63 km2, respectively. These areas represent 1.58%, 3.48%, 6.88%, and 88.05% of the total habitat area, respectively. The potential distribution area of B. racemosa demonstrated significant variations under three climate scenarios (SSP126, SSP245, and SSP585), particularly in Asia, Africa, and Oceania. Both low and high suitable areas experienced a slight increase in distribution. In summary, the research suggests that B. racemosa primarily flourishes in coastal regions of tropical and subtropical areas near the equator, with temperature and precipitation playing a significant role in determining its natural range. This study offers important implications for the preservation and control of B. racemosa amidst habitat degradation and climate change threats. Through a comprehensive understanding of the specific habitat needs of B. racemosa and the implementation of focused conservation measures, efforts can be made to stabilize and rejuvenate its populations in their natural environment.

Metal‐Organic Chemical Vapor Deposition Grown Low‐Temperature Aluminum Nitride Gate Dielectric for Gallium Nitride on Si High Electron Mobility Transistor

Gate dielectrics for gallium nitride (GaN) high electron mobility transistor (HEMT) technology have always been challenging because of the nonideal semiconductor–dielectric interface, which leads to electronic traps. Plasma‐enhanced chemical vapor deposition and atomic layer deposition are standard techniques, but they require surface treatment and post‐annealing to control these traps. This article explores metal organic chemical vapor deposition‐grown in situ aluminum nitride (AlN) as a gate dielectric. The interface is expected to be pristine as there is no change in the chamber environment. A thin (10 nm) AlN layer is deposited at a low temperature to minimize strain and prevent the formation of an unwanted conductive channel within the device. The electrical and structural properties of this AlN‐capped HEMT are compared to a standard GaN‐capped HEMT, including temperature‐dependent studies. The results show that the AlN‐capped HEMT retains a higher charge in the channel while having an order of magnitude lower gate leakage than the GaN‐capped sample. Furthermore, the AlN‐capped HEMT performs similarly to the GaN‐capped HEMT in terms of temperature‐dependent leakage, dynamic on‐resistance, and temperature coefficient of resistance.

The entropy effect on the structure and microwave dielectric properties of high-entropy Lix(MgZnCoNi)(1-x)/4Al2O4-δ ceramics

In present study, high-entropy Lix(MgZnCoNi)(1-x)/4Al2O4-δ ceramics (x = 0.00–0.45) were synthesized using solid-state reaction route, which formed a single-phase spinel structure with a Fd-3m space group. The reduction in unit cell volume and lattice parameters were attributed to the compression of polyhedral structures. A moderate content of Li+ ions promoted the grain growth and improved the densification of ceramics. The internal connection among the conformational entropy (ΔSconfig), structure, and microwave dielectric properties in high-entropy Lix(MgZnCoNi)(1-x)/4Al2O4-δ ceramics was systematically studied. The dielectric constant (εr) was largely affected by the polarizability, and relatively high conformational entropy helped to increase the phonon vibrational energy and enhance the bond strength, resulting in low εr values. Additionally, the high concentration of oxygen vacancies, high packing fraction, low internal strain/fluctuation and suppressed damping behavior were closely related to relatively low conformational entropy. Notably, the introduction of oxygen vacancy leaded to the Al3+ ions preferentially occupy tetrahedral sites enhancing the covalency. These factors collectively reduced the intrinsic losses and improved the quality factor (Q×f). Moreover, relatively high conformational entropy conduced to the structural stability by improving the M-O (M = Li, Mg, Zn, Co, and Ni) bond strength and valence, which contributes to achieve near-zero temperature coefficient of resonant frequency (τf). As ΔSconfig changes, high-entropy Lix(MgZnCoNi)(1-x)/4Al2O4-δ ceramics presented great microwave dielectric properties: εr values of 5.46 ∼ 8.49, Q×f values of 3,540 GHz (f = 14.84 GHz) ∼ 56,950 GHz (f = 12.99 GHz), and τf values of −58 ppm/°C∼ −14 ppm/°C. Our study demonstrates that the high-entropy strategy effectively enhances microwave dielectric properties. This approach has potential applications across a broad spectrum of microwave dielectrics ceramics.