Influences of phase transition and microstructure on dielectric properties of Bi<Subscript>0.5</Subscript>Na<Subscript>0.5</Subscript>Zr<Subscript>1-x</Subscript>Ti<Subscript>x</Subscript>O<Subscript>3</Subscript> ceramics

Bismuth sodium zirconate titanate ceramics with the formula Bi_0.5Na_0.5Zr_1-xTi_xO₃ [BNZT], where x = 0.3, 0.4, 0.5, and 0.6, were prepared by a conventional solid-state sintering method. Phase identification was investigated using an X-ray diffraction technique. All compositions exhibited complete solubility of Ti⁴⁺ at the Zr⁴⁺ site. Both a decrease of unit cell size and phase transition from an orthorhombic Zr-rich composition to a rhombohedral crystal structure in a Ti-rich composition were observed as a result of Ti⁴⁺ substitution. These changes caused dielectric properties of BNZT ceramics to enhance. Microstructural observation carried out employing SEM showed that average grain size decreased when addition of Ti increased. Grain size difference of BNZT above 0.4 mole fraction of Ti⁴⁺ displayed a significant increase of dielectric constant at room temperature.     

Enhanced pyroelectric properties of lead-free BNT-BA-KNN ceramics for thermal energy harvesting

In this work, (1−x)(0.98Bi_0.5Na_0.5TiO₃-0.02BiAlO₃)-x(Na_0.5K_0.5)NbO₃ (BNT-BA-xKNN) lead-free pyroelectric ceramics were prepared by a solid-state reaction method. The effect of Na_0.5K_0.5NbO₃ (KNN) content on microstructure, phase transition, and electrical properties of the BNT-BA-xKNN ceramics were systematically investigated. The results show that the appropriate content of KNN can induce the formation of the tetragonal structure, which results in the decreased ferroelectric-antiferroelectric phase transition temperature as a result of the break of long-range translational symmetry of BNT lattices. Therefore, the ferroelectric and pyroelectric properties of the BNT-BA-xKNN near room temperature are improved. The room-temperature pyroelectric coefficient significantly increases from 3.66 × 10⁻⁴ C/m²/K at x = 0 to 8.04 × 10⁻⁴ C/m²/K at x = 0.02, making a great contribution to the superior pyroelectric energy harvesting. The output energy density in one cycle of the BNT-BA-0.02KNN is 23.32 μJ/cm³, which is twice as high as that of the pristine samples. The enhancement of material properties suggests that the pyroelectric energy harvesting can be efficiently optimized by the adequate control of the phase structure.     

Colossal permittivity in TiO2 co‐doped by donor Nb and isovalent Zr

Effect of isovalent Zr dopant on the colossal permittivity (CP) properties was investigated in (Zr + Nb) co‐doped rutile TiO₂ ceramics, i.e., Nb_0.5%Zr_xTi_1?xO₂. Compared with those of single Nb‐doped TiO₂, the CP properties of co‐doped samples showed better frequency‐stability with lower dielectric losses. Especially, a CP up to 6.4 × 10⁴ and a relatively low dielectric loss (0.029) of x = 2% sample were obtained at 1 kHz and room temperature. Moreover, both dielectric permittivity and loss were nearly independent of direct current bias, and measuring temperature from room temperature to around 100°C. Based on X‐ray photoelectron spectroscopy, the formation of oxygen vacancies was suppressed due to the incorporation of Zrions. Furthermore, it induced the enhancement of the conduction activation energy according to the impedance spectroscopy. The results will provide a new routine to achieve a low dielectric loss in the CP materials.     

Enhanced pyroelectric response from domain-engineered lead-free (K0.5Bi0.5TiO3-BaTiO3)-Na0.5Bi0.5TiO3 ferroelectric ceramics

Enhanced pyroelectric response is achieved via domain engineering from [001] grain-oriented, tetragonal-phase, lead-free 0.2(2/3K_0.5Bi_0.5TiO₃-1/3BaTiO₃)-0.8Na_0.5Bi_0.5TiO₃ (KBT-BT-NBT) ceramics prepared by a templated grain growth method. The [001] crystallographic orientation leads to large polarization in tetragonal symmetry; therefore, texturing along this direction is employed to enhance the pyroelectricity. X-ray diffraction analysis revealed a Lotgering factor (degree of texturing) of 93 % along the [001] crystallographic direction. The textured KBT-BT-NBT lead-free ceramics showed comparable pyroelectric figures of merit to those of lead-based ferroelectric materials at room temperature (RT). In addition to the enhanced pyroelectric response at RT, an enormous enhancement in the pyroelectric response (from 1750 to 90,900 μC m^?2 K^?1) was achieved at the depolarization temperature because of the sharp ferroelectric to antiferroelectric phase transition owing to coherent 180° domain switching. These results will motivate the development of a wide range of lead-free pyroelectric devices, such as thermal sensors and infra-red detectors.     

Enhanced energy storage density and high efficiency of lead-free Ca1-xSrxTi1-yZryO3 linear dielectric ceramics

Ca_1-xSr_xTi_1-yZr_yO₃ (0.40 ≤ x ≤ 0.60, 0.1 ≤ y ≤ 0.4) ceramic samples were fabricated by conventional solid state method. The microstructure of ceramic samples were studied by XRD and SEM, and the influence of Zr⁴⁺ doping on the electric properties and energy storage performances were systematically studied. The results showed that the introduction of Zr⁴⁺ results in an inhibition of interfacial polarization and enhancement of grain boundary barrier effect. Ca_0.5Sr_0.5Ti_1-yZr_yO₃ ceramic samples exhibit excellent energy storage properties, with breakdown strength being on the order of 390 kV/cm versus 280 kV/cm for the counterpart Ca_0.5Sr_0.5TiO₃ ceramic samples, together with energy efficiency above 95%. Meanwhile, a maximum breakdown strength of 390 kV/cm, a high energy storage density of 2.05 J/cm³ and an ultrahigh energy efficiency of 85% at high temperature of 125 ℃ were obtained in the sample with y = 0.1 as well, indicating it as a good candidate for linear energy storage fileds.     

A-site compositional modulation in barium titanate based relaxor ceramics to achieve simultaneously high energy density and efficiency

Dielectric ceramics capacitors (DCC) with excellent energy storage performance (ESP) and charge-discharge performance (CDP) is very critical in the field of advanced electronics and power systems. A strategy that improves the ESP of 0.6Ba(Zr_0.2Ti_0.8)O₃-0.4(Na_0.5Bi_0.5)TiO₃ (BZT-NBT) ceramics was proposed via Sr²⁺ doping. XRD and SEM results confirmed that 0.6(Ba_1-xSr_x)(Zr_0.2Ti_0.8)O₃-0.4(Na_0.5Bi_0.5)TiO₃ (x = 0, 0.1, 0.2, 0.3, 0.4) (BSZT-NBT) ceramics formed dense and stable perovskite solid solutions. The relaxor ferroelectric (RFE) properties of BSZT-NBT ceramics were also well proved by dielectric behaviors. A large recoverable energy storage density (W_rec) and large efficiency (η) of 3.72 J cm⁻³ and 94.03 % (x = 0.3) can be simultaneously obtained at 289 kV cm^-1. ESP of BSZT-NBT (x = 0.3) ceramics at 180 kV cm^-1 exhibit good frequency (1−100 Hz) and temperature (room temperature (RT)-120 °C) stability. BSZT-NBT (x = 0.3) ceramics at 120 kV cm⁻¹ exhibit a prominent power density (P_D) and rapid discharge rate (t_0.9) of of 37.62 MW cm⁻³ and 70.6 ns. All evidences confirm that introduction of Sr²⁺ into A-site of barium titanate-based ceramics could effectively improve ESP.     

Tuning the ferroelectric-relaxor transition temperature in NBT-based lead-free ceramics by Bi nonstoichiometry

In this study, the Bi-nonstoichiometric 0.99Bi_x(Na_0.8K_0.2)_0.5TiO₃-0.01SrTiO₃ (BNKST) ceramics with x = 0.5–0.535 mol (Bi50-Bi53.5) were prepared by a conventional solid-state reaction method. The effects of Bi excess on structural transition and ferroelectric stability of BNKST ceramics were systematically investigated by the Raman spectra, dielectric analyses and electromechanical measurements. The introduction of excess Bi³⁺ could significantly break the long-range ferroelectric order and favor the presence of relaxor phase, then the ferroelectric-relaxor transition temperature (T_FR) can be effectively tuned to around room temperature by Bi nonstoichiometry, giving rise to an enhanced room-temperature strain property. The positive strain S_pos and dynamic piezoelectric constant d₃₃^* of Bi52.5 critical composition reach 0.33% and 440 pm/V, respectively at 6 kV/mm. The high recoverable strain of Bi52.5 sample can be attributed to the electric-field-induced reversible relaxor-ferroelectric phase transition. The present work may be helpful for further understanding and designing high-performance NBT-based lead-free ceramics for piezoelectric actuator applications.     

Mn doping effects on electric properties of 0.93(Bi0.5Na0.5)TiO3‐0.07Ba(Ti0.945Zr0.055)O3 ceramics

The validity of Mn element on 0.93(Bi_0.5Na_0.5)TiO₃‐0.07Ba(Ti_0.945Zr_0.055)O₃ ceramics (BNT‐BZT‐xMn) is certified by doping. On account of multiple effects introduced by Mn, the appropriate Mn content facilitates property improvement effectively. Compared with pure BNT‐BZT, d₃₃ of the component x = 0.25 increases about 8% up to 187 pC/N and Q_m of the component x = 1 increases about 84% up to 197. Thermally stimulated depolarization currents (TSDC) measurement reveals Mn additive is helpful to pyroelectric properties as well. The Mn‐doped component x = 0.125 exhibits better pyroelectric performance at room temperature. Corresponding pyroelectric coefficient and the figures of merit reach up to 0.061 μC/(cm² °C), F_i=217 pm/V, F_ν = 0.023 m²/C, and F_d = 12.6 μPa^?1/2, respectively, even superior to lead‐based ceramics. Similar pyroelectric advantage is also observed in the component x = 0.5 near depolarization temperature T_d. Mn doping has slight harmful influence on the ferroelectric‐to‐relaxor transition temperature T_F?R, as well as T_d, but hardly shows restriction on application. These results confirm Mn doping is an available strategy to improve BNT‐based ceramics. Therefore, Mn‐doped BNT‐BZT ceramics will be excellent candidates in area of high‐power piezoelectric application and pyroelectric detectors.     

Mechanical and thermal expansion studies on Ca0.5Sr0.5Zr4-xTixP6O24 ceramics

Ca_0.5Sr_0.5Zr_4-xTi_xP₆O₂₄ (x?=?0?0.2) ceramics belonging to the NZP family were prepared and dense ceramics with no microcracks were obtained. All of the ceramic samples were still composed of the typical NZP structure with a small amount of Ti⁴⁺ substitution for Zr⁴⁺. The mechanical and thermal expansion properties of the ceramics were characterized and the result showed that the flexural strength monotonically increased to 66.5?MPa. The thermal expansion coefficient varied from 1.8 to 3.4?×?10^?6/°C with Ti⁴⁺ content increasing. Thus, it was clear that the substitution of Ti⁴⁺ for Zr⁴⁺ had obvious effects on the sinterability, mechanical and thermal expansion properties of Ca_0.5Sr_0.5Zr_4-xTi_xP₆O₂₄ ceramics, which were discussed in detail.     

Enhanced energy-storage properties in Zr4+-modified (Bi0.4Ba0.2K0.2Na0.2)TiO3 high-entropy ceramics

Recently, high-entropy perovskite oxides (HEPOs) have received increasing interest for energy storage applications owing to their unique structure, huge composition space, and promising properties. However, designing HEPOs with improved energy storage performance remains a challenge. In this study, various HEPOs were designed by partially replacing Zr⁴⁺ for Ti⁴⁺ in (Bi_0.4Ba_0.2K_0.2Na_0.2)TiO₃ medium-entropy ferroelectric ceramics. The resulting ceramics exhibited a pseudo-cubic structure. With increasing Zr⁴⁺ content, the ceramics gradually transformed into relaxor ferroelectrics. The energy storage performance of the ceramics depended on the Zr⁴⁺ content. The sample with 20 mol% Zr⁴⁺ showed the best energy storage performance with a maximum reversible energy density of 2.47 J/cm³ and an energy storage efficiency of 82.3% at a low applied electric field (224 kV/cm). This study obtained a promising material for the new generation dielectric energy storage capacitors and provided a novel method for enhancing energy storage performance.     

Phase stability and thermo-physical properties of ZrO2-CeO2-TiO2 ceramics for thermal barrier coatings

The properties of ZrO₂ co-stabilized by CeO₂ and TiO₂ ceramic bulks were investigated for potential thermal barrier coating (TBC) applications. Results showed that the (Ce_0.15Ti_x)Zr_0.85-xO7 (x?=?0.05, 0.10, 0.15) compositions with single tetragonal phase were more stable than the traditional 8YSZ at 1573?K. These compositions also showed a large thermal expansion coefficient (TEC) and a high fracture toughness, which were comparable to those of YSZ. However, the phase stability, fracture toughness and sintering resistance of the CeO₂-TiO₂-ZrO₂ system showed a decline tendency with the increase of TiO₂ content. The TEC of the ceramic bulks decreased with increase of TiO₂ content as well because the crystal energy was enhanced with increasing substitution of Zr⁴⁺ by smaller Ti⁴⁺. The (Ce_0.15Ti_0.05)Zr_0.8O₂ had the best comprehensive properties among the (Ce_0.15Ti_x)Zr_0.85-xO₂ compositions as well as a low thermal conductivity. Therefore, it can be explored as a TBC candidate material for high-temperature applications.     

Field-induced large strain in lead-free 0.99[(1−x) Bi0.5(Na0.80K0.20)0.5TiO3–xBiFeO3]–0.01(K0.5Na0.5)NbO3 piezoelectric ceramics

Lead-free 0.99[(1−x) Bi_0.5(Na_0.80K_0.20)_0.5TiO₃–xBiFeO₃]–0.01(K_0.5Na_0.5)NbO₃ (BNKT20–100xBF–1KNN) piezoelectric ceramics were fabricated through conventional techniques. Results showed that changes in BF content of BNKT20–100xBF–1KNN induced transition from the ferroelectric phase to the ergodic relaxor phase. These changes also significantly disrupted long-range ferroelectric order, thereby correspondingly adjusting the ferroelectric-relaxor transition point T_F-R to room temperature. A large strain of 0.39% at the electric-field of 80 kV/cm (corresponding to a large signal d₃₃^* of 488 pm/V) was obtained at x=0.06, which originated from the composition proximity to the ferroelectric-relaxor phase boundary. Moreover, the high-strain material exhibited exceptional fatigue resistance (up to 10⁶ cycles) as a result of the reversible field-induced phase transition. The proposed material exhibits potential for novel ultra-large stroke and nonlinear actuators that require enhanced cycling reliability.     

Electric-field-temperature phase diagram and electromechanical properties in lead-free (Na0.5Bi0.5)TiO3-based incipient piezoelectric ceramics

In this work, the (1-x)(0.8Na_0.5Bi_0.5TiO₃-0.2K_0.5Bi_0.5TiO₃)-xSrTiO₃ (NKBT-xST) incipient piezoelectric ceramics with x = 0–0.07 (0ST-7ST) were prepared by the solid-state reaction method and their structural transformation and electromechanical properties were investigated as a function of ST content. As the ST content increases, the long-range ferroelectric order is disrupted, and the ferroelectric-relaxor phase transition temperature (T_FR) shifts to around room temperature for NKBT-5ST ceramics, accompanied by a relatively high electrostrain of 0.3% at 6 kV/mm. The large strain response associated with the vanished ferroelectric properties around T_FR can be attributed to the reversible relaxor-ferroelectric phase transition. The electric-field-temperature (E-T) phase diagrams were established, and the transition between the two field-induced long-range ferroelectric states were found to take place via a two-step switching process through an intermediate relaxor state. The threshold electric field to trigger the conversion between ferroelectric state and relaxor state depends strongly on the dynamics of polarization relaxation, which is influenced by temperature and composition.     

Diffusion Characteristics of Zr4+ in LiNbO3 Single‐Crystal

Diffusion characteristics of Zr⁴⁺ in LiNbO₃ single‐crystal were studied. Zr⁴⁺‐doped LiNbO₃ crystal plates were prepared by in‐diffusion of 100 nm thick ZrO₂ film coated onto Z‐cut congruent substrates in wet O₂ at different temperatures. Zr⁴⁺‐diffused profile was analyzed by secondary ion mass spectrometry. The results show that the Zr⁴⁺ diffusion follows the traditional diffusion theory. From the measured profiles, important diffusion parameters are obtained, such as diffusivity and its temperature dependence, diffusion constant, activation energy, surface concentration, and solubility. The Zr⁴⁺ has a diffusivity similar to that of Ti⁴⁺, implying that the Zr⁴⁺ doping and the Ti⁴⁺ diffusion can be performed simultaneously to simplify the fabrication process of a photorefractive‐damage‐resistant Zr⁴⁺‐doped Ti‐diffused LiNbO₃ waveguide.     

Giant electric field-induced strain at room temperature in LiNbO3-doped 0.94(Bi0.5Na0.5)TiO3-0.06BaTiO3

We report experimental investigation on the ferroelectricity and electric field-induced strain response in LiNbO₃-doped 0.94(Bi_0.5Na_0.5)TiO₃-0.06BaTiO₃ (BNT-BT) piezoelectric ceramics. At room temperature, a large strain of 0.6% (at 70 kV/cm) is achieved in the 2.5%-LiNbO₃-doped BNT-BT, higher than that of commercially-utilized Pb(Zr,Ti)O₃. The corresponding piezoelectric coefficient d^*₃₃ reaches 857 pm/V, which is high among these of BNT-based ceramics at room temperature. Further study indicates that the superior piezoelectric properties are realized at the ferroelectric-relaxor transition temperature T_F-R, which is pushed to room temperature with 2.5% LiNbO₃ doping. This indicates that large electromechanical response can be induced via delicate mixing of the ferroelectric rhombohedral phase and the polar nanoregions (PNRs) relaxor-ferroelectric tetragonal phase.     

Ferroelectric,dielectric and pyroelectric properties of Sr and Sn codoped BCZT lead free ceramics

The 1?mol.-%Sr and 1?mol.-%Sn codoped (Ba_0·84Ca_0·15Sr_0·01)(Ti_0·90Zr_0·09Sn_0·01)O₃ (BCSTZS) ceramics were synthesised by the normal solid state sintering method. The electric field and temperature dependence of the ferroelectric properties of the BCSTZS ceramics were investigated. Their energy storage density depending on electric field and temperature was determined from the polarisation–electric field (P–E?) hysteresis loops. According to the dielectric analysis, the BCSTZS ceramics experience three-phase transitions upon cooling. At room temperature, the pyroelectric coefficient p calculated from the remnant polarisation–temperature (P_r–T?) curve is 1116·7?μC?K^??1?m^??2, and the figures of merit F_d is 18·1?μPa^??1/2, F_v is 0·013?m²?C^??1 and F_i is 479·3?pm?V^??1 respectively. The pyroelectric figures of merit exhibit high frequency stability over a wide range from 100 to 2000?Hz, whereas these values vary gradually with the increase in temperature, which deserves further research to improve their stability. The excellent pyroelectric property of the BCSTZS ceramics is considered as correlating with a polymorphic phase transition occurring around room temperature. The present study demonstrates that the lead free BCSTZS ceramics are promising candidate for replacing the lead zirconate titanate based ceramics.     

Frequency and temperature independent (Nb0.5Ga0.5)x(Ti0.9Zr0.1)1-xO2 ceramics with giant dielectric permittivity and low loss

Nb⁵⁺ and Ga³⁺ co-doped Ti_0.9Zr_0.1O₂ ceramics were synthesized using the conventional solid-state reaction method. Single rutile-liked phase of octahedron structure were identified for all compositions in (Nb_0.5Ga_0.5)_x(Ti_0.9Zr_0.1)_1-xO₂ (NGT) with x = 0.01 to 0.10 by X-ray diffraction patterns coupled with Rietveld refinement. Microstructural scanning image, together with energy dispersive x-ray spectroscopy (EDX), revealed good chemical homogeneity in NGT samples. A giant dielectric permittivity of 5 × 10⁴ and a low loss of 0.02 was obtained in NGT with x = 0.01 due to the contribution of electron-pinned and defect-dipole effect. Furthermore, a temperature (-20–120 °C), frequency (0.1–10⁴ Hz) and bias electric field (100–200 V/mm) independent dielectric permittivity and loss was found in this composition, which is critical for potential applications of supercapacitors.     

Zr4+/Ti4+ Codiffusion Characteristics in Lithium Niobate

Zr⁴⁺/Ti⁴⁺‐codoped LiNbO₃ plates were prepared by local codiffusion of stacked ZrO₂ and Ti metal films coated onto Z‐cut congruent LiNbO₃ substrates in wet O₂ at 1060°C. The metal and oxide films have different thicknesses and coating sequences. After diffusion, the Zr⁴⁺ doping effect on the refractive index of LiNbO₃ and the Li₂O out‐diffusion issue were studied by the prism coupling technique. The codiffusion characteristics of Zr⁴⁺ and Ti⁴⁺ were studied by secondary ion mass spectrometry. The results show that the Zr⁴⁺ doping has little contribution to the refractive index of the crystal. Li₂O out‐diffusion is not measurable. In the Zr⁴⁺‐only diffusion case, the diffusivity of Zr⁴⁺ is four times smaller than that of Ti⁴⁺. In the Zr⁴⁺/Ti⁴⁺ codiffusion case, the Ti⁴⁺ codiffusion assists the Zr⁴⁺ diffusion. The Zr⁴⁺ diffusivity increases linearly by two more times with the increase in initial Ti film thickness from 0 to 200 nm. On the other hand, the Zr⁴⁺ affects the Ti⁴⁺ diffusion little. Neither the ZrO₂ film thickness nor the coating sequence of Ti metal and ZrO₂ oxide films influences the diffusivity of the two ions. All the codiffusion characteristics are explained. A Zr⁴⁺/Ti⁴⁺ codiffusion model is suggested that consists of two independent diffusion equations with a Zr⁴⁺ diffusivity dependent of Ti⁴⁺ concentration and a constant Ti⁴⁺ diffusivity. In addition, the existence of a waveguide in the Zr⁴⁺/Ti⁴⁺‐codoped layer is verified experimentally, and the optical‐damage‐resistant feature of the waveguide is verified by two‐beam hologram recording experimental results.     

Enhanced thermal stability of piezoelectricity in lead-free (Ba,Ca)(Ti,Zr)O3 systems through tailoring phase transition behavior

Good thermal stability in lead-free BaTiO₃ ceramics is important for their applications above room temperature. In this study, thermal stable piezoelectricity in lead-free (Ba,Ca)(Ti,Zr)O₃ ceramics was enhanced by tailoring their phase transition behaviors. Comparison between (1-x)Ba(Ti_0.8Zr_0.2)O₃-x(Ba_0.65Ca_0.35)TiO₃ and (1-y)Ba(Ti_0.8Zr_0.2)O₃-y(Ba_0.95Ca_0.05)TiO₃ revealed that latter system at y?=?0.80 had much better thermal stable piezoelectric coefficient than the former at x?=?0.45. Both systems crystalized in tetragonal to orthorhombic phase boundary at room temperature. The phase transition temperature and degree of diffusion were adjusted by Ca and Zr ions contents and demonstrated great influence on temperature dependent dielectric permittivity, hysteresis loops, and in-situ domain structures. The improved thermal stability of (1-y)Ba(Ti_0.8Zr_0.2)O₃-y(Ba_0.95Ca_0.05)TiO₃ prepared at y?=?0.80 was linked to its higher paraelectric to ferroelectric phase transition temperature (T_m?=?115.7?°C) and less degree of diffusion (degree of diffusion constant γ?=?1.35). By comparison, (1-x)Ba(Ti_0.8Zr_0.2)O₃-x(Ba_0.65Ca_0.35)TiO₃ prepared at x?=?0.45 revealed T_m?=?81.3?°C and γ?=?1.65. Overall, these findings look promising for future stimulation of phase transition behaviors and design of piezoelectric materials with good thermal stabilities.     

Correlation between the structure and modified microwave dielectric characteristics of Zr4+ substituted Ni0.4Zn0.6Ti(1-x)ZrxNb2O8 ceramics

Microwave ceramics are an important classes of materials that are used in microwave communication systems, especially in the area of 5G wireless communication and the internet of things. In this work, to improve the Q×f values and enhance the temperature stability of Ni_0.4Zn_0.6TiNb₂O₈ ceramics, the influence of the substitution of Zr⁴⁺ ions at the Ti site in Ni_0.4Zn_0.6Ti_(1-x)Zr_xNb₂O₈ ceramics was investigated. The Q×f value increases from 32114 GHz to 45733 GHz and the τ_f value changes from 38.1 ppm/°C to 3 ppm/°C with a slight Zr⁴⁺ ion substitution (x = 0.1). Meanwhile, the sample with the Zr⁴⁺ ion substitution (x = 0.3) that was sintered at 1120 °C shows a very high Q×f value of 92078 GHz. Furthermore, the XRD results reveal that the phase and structure of the Ni_0.4Zn_0.6Ti_(1-x)Zr_xNb₂O₈ ceramics change with the different Zr⁴⁺ ion contents. The substitution of the Zr⁴⁺ ion can promote the sintering process for the Ni_0.4Zn_0.6Ti_(1-x)Zr_xNb₂O₈ ceramics and restrain the Ni_0.5Ti_0.5NbO₄ phase formation. The results obtained from Ni_0.4Zn_0.6Ti_(1-x)Zr_xNb₂O₈ ceramics can offer useful information for the study and application of high-frequency microwaves.