Structure Refinement Research Articles

Microstructure and strength of cold-drawn large strain Fe35Ni35Cr20Mn10 high-entropy alloy

The Fe35Ni35Cr20Mn10 high-entropy alloy wires can achieve a large strain of 8.73 and a section reduction ratio of 99.98 %,and possess a high strength of 1868 MPa via traditional wire drawing. The microstructure evolution and mechanical properties of cold-drawn Fe35Ni35Cr20Mn10 high-entropy alloy are characterized by microstructure observation and tensile test. The results showed that The Fe35Ni35Cr20Mn10 HEA has excellent plastic forming capacity and excellent phase stability during plastic deformation. The Fe35Ni35Cr20Mn10 HEA has excellent continuous drawing ability, the main deformation mechanism is the plane slip and cross slip of the dislocation and the dynamic recovery of the sublamellar layer make the lamellar structure maintain a dynamic equilibrium state, and the lamellar thickness is basically unchanged to support the continuous plastic deformation under high strain conditions. The dynamic balance of coarsening and refining of lamellar structure in the process of plastic deformation is mainly due to the merging of HEA lamellar caused by the movement of trigeminal node induced by strain. Texture evolution showed that the <111> and <100> fiber textures were the stable texture component and the texture component content remained unchanged even under further increased strain. The Fe35Ni35Cr20Mn10 high-entropy alloy wire with high strain of 8.73 possesses excellent strength, and its tensile strength is 1868 MPa at room temperature, which has the largest strain. The dislocations proliferation, lamellar structure refinement and texture strengthening lead to high strength of the Fe35Ni35Cr20Mn10 high-entropy alloy wire.

Lattice symmetry relaxation as a cause for anisotropic line broadening and peak shift in powder diffraction.

In powder diffraction, lattice symmetry relaxation causes a peak to split into several components which are not resolved if the degree of desymmetrization is small (pseudosymmetry). Here the equations which rule peak splitting are elaborated for the six minimal symmetry transitions, showing that the resulting split peaks are generally broader and asymmetric, and suffer an hkl-dependent displacement with respect to the high-symmetry parent peak. These results will be of help in Rietveld refinement of pseudosymmetric structures where an exact interpretation of peak deformation is required.

Multicenter Experience with the Pipeline Flex and Vantage with Shield Technology for Intracranial Aneurysm Treatment.

The Pipeline Embolization Device is a safe and effective treatment option for intracranial aneurysms. The newer Pipeline generations have received structural refinements and a surface modification to improve deliverability, procedural safety, and angiographic outcomes. This multicenter study evaluated the clinical safety and efficacy of the 2 surface-modified Pipeline iterations, Pipeline Vantage and Pipeline Flex with Shield Technology (PFS). Consecutive patients treated between 2017 and 2023 were retrospectively reviewed for aneurysm characteristics, procedural details, complications, and angiographic outcomes. The safety end point was the rate of procedural and postprocedural major neurologic events occurring during the hospital stay. The efficacy end point was the rate of complete occlusion at last follow-up. One hundred forty-one patients underwent 112 Pipeline Vantage procedures and 32 PFS procedures for 147 aneurysms with a mean size of 8.0 (SD, 5.9) mm (11% ruptured, 16% posterior circulation, 18% nonsaccular morphology). All procedures were technically successful with a mean of 1.2 devices implanted. Balloon angioplasty was required in 20/144 (13.9%) procedures. Major neurologic adverse events occurred in 6/144 (4.2%) procedures (all ischemic stroke), resulting in death in 2 (1.4%) patients. There were no hemorrhagic complications. At a mean of 11 months, complete occlusion was achieved in 85/112 (75.9%) aneurysms, 15/112 (13.4%) had an entry remnant, and 12/112 (10.7%) had an aneurysm remnant. The results demonstrate high feasibility, procedural safety, and efficacy of the surface-modified Pipeline flow diverters.

Towards enhanced elevated-temperature mechanical properties by regulation of eutectic structure in Al-Cu-Si alloys solidified under super-gravity field

High volume fraction of tri-phase eutectic structure is challenging to obtain in ternary alloys through conventional methods. Currently, we reported that super-gravity solidification can be utilized to obtain high-volume fraction Al-Al2Cu-Si tri-phase eutectic structure in Al-Cu-Si alloys. The refinement of the eutectic structure can be detected mainly due to the enhancement of mass transfer, affecting the nucleation rate and growth of eutectic phase in the Al-Cu-Si eutectic system. Interestingly, the refined Al2Cu and Si eutectic structures are stable even up to 300 °C thermal exposure without obvious coarsening, contributing to the enhancement of elevated-temperature mechanical properties (∼268.8±8.8 MPa at 300 °C), which is ∼51.9 % higher than those solidified under normal gravity field (∼177.0±1.9 MPa). The refinement and homogeneous distribution of more Al-Al2Cu-Si tri-phase eutectic structures provide better stress dispersion, favoring crack initiation and propagation within the tri-phase eutectics, resulting in a transition from brittle fracture to ductile fracture mode.

Fine structural analysis of calcium–niobium–gallium garnet (CNGG) by single-crystal anomalous X-ray scattering

Single-crystal anomalous X-ray scattering (AXS) experiments were conducted to investigate the cation distribution of calcium–niobium–gallium garnet (CNGG). AXS measurements suggested an ordered distribution of Nb at the octahedral site, and further structural refinement allowed us to obtain the structural formula Ca3Nb1.703(0) Ga3.162(2)O12. Ca was only located in the dodecahedral site, while Ga was distributed in the octa- and tetrahedral sites. The tetrahedral site had a significant number of vacancies at a ratio of one vacancy per unit cell, and the Nb/Ga occupation ratio at the octahedral site results in non-stoichiometric chemical composition of CNGG and its unique broad absorption wavelength.The findings of this study can contribute to device fabrication, property optimization, and quality control processes related to CNGG.

Structural determination, energy transfer and color-tunable photoluminescence of stable LiYSiO4: Ce/Tb/Sm Phosphors toward nUV pumped wLEDs application

Study on photon emission of Ce3+-doped phosphors is essential for advanced optoelectronic application. However, it remains quite difficult to design near-ultraviolet excitable Ce3+-activated silicate blue/cyan-emitting phosphors because of the combined influence of iconicity of Ce3+, crystal field strength, and nephelauxetic effect. Herein, Ce3+ incorporated into a proper host LiYSiO4 (LYS) phosphor is mechanistically investigated and shown efficient blue/cyan photoluminescence (PL) owing to Ce3+ 5d1 electronic state experiencing appropriate crystal field splitting. The comprehensive analysis based on structural refinement, dynamic/static spectra, and density functional theory calculations indicates that Ce3+ ions are energetically favored in octahedral Y site as compared with Li site in the host, resulting in attractive PL properties. According to the principle of color superposition and via cascading energy transfer (ET) from Ce3+ → Tb3+ → Sm3+, systematic PL tuning in a large color gamut is realized by further codoping with the green- and red-emissions of Tb3+ and Sm3+ in the phosphor LYS: Ce3+/Tb3+/Sm3+. The direct ET from Ce3+ → Sm3+ is difficult to occur due to the metal-metal charge transfer effect. Of note, the PL thermal-quenching of Ce3+ is mainly associated with multiphonon relaxation, while the quenching of Tb3+/ Sm3+ is primarily due to the cross relaxation (CR) process via dipole-dipole (d-d) interaction. The appropriate distance between the two nearest adjacent Y sites in the host together with the ET are conducive to weaken the CR process of Tb3+/Sm3+, leading to high PL efficiency. Finally, a prototype pc-wLED assembled via a remote ‘capping’ packaging strategy and by using only the stably composition-optimized white-emitting LYS: Ce3+/Tb3+/Sm3+ demonstrates that the phosphor is promising for high-quality of light.

Ca2HfSi4O12:Eu2+: A novel blue phosphor with excellent temperature sensitivity for temperature sensor and cathodoluminescence properties for field-emission displays

A new silicate blue phosphor Ca2HfSi4O12:Eu2+ (CHSO:Eu2+) was designed and synthesized via a solid-state reaction. The structure of CHSO:Eu2+ was analyzed by structure refinement. The electronic structure of CHSO was calculated using first-principles calculations, revealing its effect on luminescence and long-persistent properties. Owing to the O vacancies in the crystal structure, undoped CHSO showed wide blue emission (400–650 nm, λmax = 486 nm) under 296 nm excitation. After being irradiated with a UV lamp for 10 min, the CHSO sample showed obvious afterglow properties that could persist for approximately 50 min above the recognizable intensity level (≥0.32 mcd m−2). CHSO:Eu2+ exhibited excellent temperature sensitivity with a relative sensitivity of 4.5 % K−1@473K, which is higher than those of other Eu2+-based temperature sensor materials. The mechanism between thermal quenching and electronic structure was proposed. Moreover, CHSO:Eu2+ shows excellent cathode ray saturation and aging resistance. This study provides a potential temperature sensor, field-emission-display material, and theoretical reference for developing high-sensitivity temperature-sensing materials.

Deep attributed graph clustering with feature consistency contrastive and topology enhanced network

Deep attributed graph clustering has attracted considerable interest lately due to its capability to uncover meaningful latent knowledge from heterogeneous spaces, thereby improving our comprehension of real-world systems. However, ensuring the consistency of the clustering assignments generated from topological and attribute information remains a key issue, which is one of the reasons for the low performance of clustering. To tackle these issues, a novel deep clustering approach with Feature Consistency Contrastive and Topology Enhanced Network (FCC-TEN) is proposed, which consists of GAT and AE that can mine the topological and attributed information and achieve consistency contrastive learning to improve clustering performance. First, a Fusion Graph Convolutional Auto-encoder module is proposed to fuse the attribute information captured by each layer of the AE and enrich topological information for improving the feature extraction capability of AE. Then, using a Feature Consistency Contrastive module to uncover consistency information of the GAT and AE through contrastive learning at the feature and label level. Finally, clustering results are obtained directly by the clustering assignment obtained at the label level. Comprehensive testing on five improved datasets shows that our method provides advanced clustering performance. Moreover, visual analyses of the clustering results corroborate a gradual refinement of the clustering structure, proving the validity of our approach.

Refinement of eutectic structure and precipitates of Cu–20Ag alloy due to Y microalloying

Copper-silver alloy rod with high mechanical properties and stable conductivity are the key materials for the preparation of microfilaments used in endoscopy and other medical fields. In this paper, the microstructure of Cu–20Ag rod was regulated by adding trace rare earth Y in order to improve the comprehensive performance of copper-silver alloy further. and studies the distribution and existence of rare earth Y as well as the influence on the performance of copper-silver alloy rod billet. The results of research show that: rare earth Y mainly exists in the branching nodes of the eutectic organization, so that the alloy in the solidification of constitutional supercooling increases, thus refining the eutectic structure, and make it uniformly distributed. After addition of 0.01 wt%Y, Cu4Y was precipitated in the eutectic structure of the rod. After adding 0.03 wt%Y, the precipitates types increased to trace intermetallic compound AgY and nanoparticles Cu4Y. The increase of the interface between eutectic structure and Cu matrix decreases the electron scattering probability. This is the main factor to lead to the decrease of electrical conductivity. The precipitation hardening of precipitated phase and the increase of interface between eutectic structure and Cu matrix are the main factors for the increase of tensile strength of bar billet. The main factor of the decrease in the conductivity of rod billet is the increase of Ag phase dissolved in eutectic structure and the interface between eutectic structure and Cu matrix.

CHARACTERIZATION OF ALUMINIUM METAL MATRIX COMPOSITES REINFORCED WITH SILICON CARBIDE AND NICKEL PARTICULATES

This research article presents the procedure for the fabrication of Aluminium alloy (LM25) based metal matrix composites containing particulates of silicon carbide (10 wt. %) and nickel (0, 5 and 10 wt. %). Using the vortex casting technique, three composites were formulated and characterized as per ASTM standards. Microstructure analysis using "scanning electron microscopy" reveals the uniform distribution of reinforcing particulates within the base matrix without clustering. "Energy dispersive spectroscopy" illustrates the presence of ingredients within the composites. "X-ray diffraction" patterns indicate the formation of mesoporous NiSiAl compound within the composite resulting from internal reactions. The "optical microscopy" reveals the refinement of grain structure with the inclusion of nickel particulates within the composites. The influence of the composition of reinforcing particulates that is, silicon carbide and nickel on the properties of the base matrix was explored. An enhancement in the microhardness, tensile strength, wear resistance and traction force and a reduction in friction coefficient was observed together with a marginal reduction in elongation and the porosity level is also under the controlled limits (&lt;5%).

Insights into Structural Changes During Scratch Deformation of Ductile Coating Systems: Plastic Flow, Microstructural Transformations, and Crack Development

This study investigates the structural changes occurring during the scratch deformation of ductile materials, focusing on a composite aluminum (Al) coating on a steel substrate fabricated using a solid-state aluminizing technique. By analyzing the results of the scratch test with transmission electron microscopy (TEM) and focused ion beam (FIB) techniques, the research provides a detailed examination of plastic flow, microstructural transformations, and crack development. Results demonstrate that strong adhesion at the interface and similar mechanical properties between steel and Al layers facilitate co-deformation, crucial for maintaining the integrity of the composite structure. The study features the formation of a rolling-like laminated structure and significant grain refinement in both the steel and Al components, driven by plastic deformation. Observed atomic-scale intermixing and the formation of an amorphous interlayer highlight extensive material interactions during deformation. The visualization of crack progression using FIB allows for an in-depth understanding of the fracture process. Subsurface cracks initiate within the thin Al interlayer and propagate toward the surface, evolving through the coalescence of nanopores into microvoids and larger cavities, ultimately leading to crack propagation. Secondary internal cracks may arise due to stress fields generated by the primary crack, contributing to a complex network of internal cracks.

Development of ultrafast four-dimensional precession electron diffraction

Ultrafast electron diffraction/microscopy technique enables us to investigate the nonequilibrium dynamics of crystal structures in the femtosecond-nanosecond time domain. However, the electron diffraction intensities are in general extremely sensitive to the excitation errors (i.e., deviation from the Bragg condition) and the dynamical effects, which had prevented us from quantitatively discussing the crystal structure dynamics particularly in thick samples. Here, we develop a four-dimensional precession electron diffraction (4D-PED) system by which time (t) and electron-incident-angle (ϕ) dependences of electron diffraction patterns (qx,qy) are recorded. Nonequilibrium crystal structure refinement on VTe2 demonstrates that the ultrafast change in the crystal structure can be quantitatively determined from 4D-PED. We further perform the analysis of the ϕ dependence, from which we can qualitatively estimate the change in the reciprocal lattice vector parallel to the optical axis. These results show the capability of the 4D-PED method for the quantitative investigation of ultrafast crystal structural dynamics.

High-pressure phase transition in clinochlore: IIa polytype stabilization

Abstract Structural variations of natural clinochlore with pressure have been studied by in situ single-crystal X-ray diffraction (XRD) in a diamond-anvil cell in the pressure range 0–20 GPa at room temperature. High-resolution XRD data allowed for the identification of a polytypic phase transition at about 9 GPa. Around 4.32(5) GPa, the unit-cell parameters exhibited a significant deviation from linear behavior, particularly the c and β values, abruptly interrupted when the phase transition occurs. XRD patterns showed a drastic reduction of diffuse scattering due to the stabilization of the high-pressure structure, suggesting that the atomic reorganization of the layers led to a disorder reduction. The phase transition showed complete reversibility during the experiment. Ab initio structural refinements identified the transition as polytypic, from the initial IIb-4 triclinic polytype (space group C1) to the IIa-1 monoclinic structure (space group C2/m), with unit-cell parameters a = 5.2058(6) Å, b = 9.0208(4) Å, c = 13.560(7) Å, β = 97.34(3)°. The latter was theoretically derived in the 1960s as the least stable chlorite polytype but has never been observed in natural chlorites. The phase transition also has a significative effect on the bulk modulus, with a reduction from K0 = 81.2(13)t to K0 = 56.0(6) GPa for the high-pressure structure. An isothermal run at 600 K from ambient pressure to 14 GPa showed the same phase transition at 7.8(5) GPa. Its occurrence at lower pressures suggests a negative P/T slope for the transition. Therefore, at high-temperature and high-pressure conditions compatible with impact phenomena, the polytypic phase transition could prevent chlorite from early destabilization and dehydration.

Printed flexible supercapacitors utilizing composites of MWCNT/MOF ultrathin nanosheets: Exploring 1D/2D structural adjustment

The self-stacking propensity of metal–organic frameworks (MOFs) during synthesis, combined with their intrinsic limitations in electrical conductivity and mechanical stability, constrains their utility as high-capacity energy sources in wearable electronics. Here, we employ a surfactant-assisted method to mitigate the Z-axis stacking of zinc metalloporphyrin organic frameworks (NMOFs), yielding ultrathin two-dimensional (2D) material sheets. By integrating carboxyl multiwalled carbon nanotubes into these nanosheets (denoted as C-NMOF-x), the lamellar structure of MOF is preserved while promoting the formation of rich multistage micropores and continuous conductive channels. This structural refinement remarkably enhances electrochemical properties, including capacitance, electronic conductivity, and cycling stability. Leveraging synergistic interactions, the resulting C-NMOF-4 composite achieves a specific capacitance of 0.152 mAh/g in a three-electrode system at a current density of 1 A/g. Furthermore, the modulated C-NMOF-4 composites are successfully formulated into homogeneous e-inks suitable for dispensing printing, enabling the mass production of flexible micro-supercapacitors (MSCs). Notably, these MSCs maintain 95 % of their capacitance even after 180° bending under wearable conditions. This surface and interface microstructure modulation strategy holds promise for enhancing the synergistic coupling effects of 2D materials and offers new avenues for the application of innovative 2D materials in wearable electronics.

Microstructure, crystallographic texture and mechanical properties of the Zn–1%Mg–1%Fe alloy subjected to severe plastic deformation

The paper covers the production, analysis of the microstructure, crystallographic texture and deformation mechanisms of the ultrafine-grained (UFG) Zn–1%Mg–1%Fe zinc alloy demonstrating unique physical and mechanical properties compared to its coarse-crystalline analogs. The zinc alloy with improved mechanical properties was developed in two stages. At the first stage, based on the analysis of literature data, an alloy with the following chemical composition was cast: Zn–1%Mg–1%Fe. Then, the alloy was subjected to high-pressure torsion (HPT) to improve mechanical properties due to grain structure refinement and implementation of dynamic strain aging. The conducted mechanical tensile tests of the samples and assessment of the alloy hardness showed that HPT treatment leads to an increase in its tensile strength to 415MPa, an increase in hardness to 144HV, and an increase in ductility to 82%. The obtained mechanical characteristics demonstrate the suitability of using the developed alloy in medicine as some implants (stents) requiring high applied loads. To explain the reasons for the improvement of the mechanical properties of this alloy, the authors carried out comprehensive tests using microscopy and X-ray diffraction analysis. The microstructure analysis showed that during the formation of the ultrafine-grained structure, a phase transition is implemented according to the following scheme: Zneutectic + Mg2Zn11eutectic + FeZn13 → Znphase + Mg2Zn11phase + MgZn2particles + Znparticles. It was found that as a result of high pressure torsion in the main phases (Zn, Mg2Zn11), the grain structure is refined, the density of introduced defects increases, and a developed crystallographic texture consisting of basic, pyramidal, prismatic, and twin texture components is formed. The study showed that the resistance of pyramidal, prismatic and twin texture components at the initial stages of high-pressure torsion determines the level and anisotropy of the strength properties of this alloy. The relationship between the discovered structural features of the produced alloy and its unique mechanical properties is discussed.

Revealing multiphase coexistence of R-O-T phases in BaTiO3-CaTiO3-BaSnO3 electroceramics for energy harvesting and storage response with piezo actuation

The (Ba1-xCax)(SnyTi1-y)O3 piezoelectric ceramics (where x=0.016, y=0.024; x=0.032, y=0.048; x=0.048, y=0.072; x=0.064, y=0.096; x=0.08, y=0.12) were designed by conventional solid state reaction method. The crystal structure for the composition of x=0.064 and y=0.096 (abbreviated as BCST-4) possesses the coexistence of non-centrosymmetric rhombohedral-orthorhombic-tetragonal (R-O-T) tri-lattice symmetries at room temperature, as demonstrated by the structural Rietveld refinement, Raman analysis, and temperature dependence of dielectric study. Because of the R-O-T multiphase coexistence, BCST-4 possesses a superior electromechanical and piezoelectric property viz. kp ∼ 0.45, strain ∼ 0.100 %, d33* ∼ 649 pm/V, and an improved d33 ∼ 452 pC/N, which is comparable to commercially available soft PZT ceramics (d33 ⁓ 370 pC/N). For BCST-4 ceramics, an exceptional electrostriction coefficient Q33 ∼ 0.0434 m4/C2 value was attained. The intrinsic piezo-actuation DC strain was observed to be 130 microstrain (με) and 188 με with ε33 and ε31 modes respectively. The BCST-4 ceramic exhibits a maximum output power of 1.03 mW, a power density of 13.5 µW/mm3, a maximum output current of 88 µA, and an open circuit voltage Vpp of 28 V which successfully glowed ‘SPPU’ panel having 40 red commercial light-emitting diodes (LEDs). The energy storage study reveals that BCST-4 ceramics exhibit a maximum energy storage density (Wrec) of 165.87 mJ/cm3 with efficiency (ƞ) 68.00 %. Therefore, the improvement in electrostriction coefficient, piezoelectric charge coefficient, and energy storage response indicates that BCST-4 ceramic has the potential for actuator, energy harvesting, and energy storage applications.

Temperature-dependent diffraction studies on the stannides Sr3Rh4Sn4, Sr3Ir4Sn4 and Sr2.43Eu0.57Ir4Sn4

Abstract The stannides Sr3Rh4Sn4 and Sr2.43Eu0.57Ir4Sn4 (Na3Pt4Ge4-type, space group I 4 ‾ $\overline{4}$ 3m) were synthesized by induction-melting of the elements in sealed tantalum tubes followed by an annealing sequence to increase the crystallinity. Their polycrystalline samples were characterized by powder X-ray diffraction and the structures were refined from single crystal X-ray diffractometer data. The basic building units are [Rh4Sn4] respectively [Ir4Sn4] stellae quadrangulae which condense to rigid three-dimensional networks. A striking crystal chemical feature of the Na3Pt4Ge4-type phases are pronounced anisotropic displacements of the divalent cations. Additional structure refinements of Sr3Rh4Sn4 and Sr2.43Eu0.57Ir4Sn4 and the previously reported stannide Sr3Ir4Sn4 at 90 K reveal less anisotropic behavior in going to lower temperatures.

Impact of in-situ CO2 injection on natural and accelerated carbonation performance of aerial lime mortar

Aerial lime is a well-known carbonatable binder. To address some limitations of slow carbonation speed and low initial strength, this study proposes an internal carbonation technique for field-casting aerial lime mortar using in-situ CO2 injection. The technique was found to be significantly effective in accelerating the carbonation and strength development of the mortar. For the first 28 days, the mortars mixed with CO2 injection showed 1.25–1.68 times faster carbonation and 1.5–2.3 times higher compressive strength than the mortar mixed without CO2 injection. This improvement can be explained by the internal carbonation effect, which effectively refines the pore structure while providing a nucleation site for subsequent carbonation. The early refinement of the pore structure also increased later carbonation performance under both natural and accelerated conditions.

Spatially resolved profiling of protein conformation and interactions by biocompatible chemical cross-linking in living cells

Unlocking the intricacies of protein structures and interactions within the dynamic landscape of subcellular organelles presents a significant challenge. To address this, we introduce SPACX, a method for spatially resolved protein complex profiling via biocompatible chemical cross(x)-linking with subcellular isolation, designed to monitor protein conformation, interactions, and translocation in living cells. By rapidly capturing protein complexes in their native physiological state and efficiently enriching cross-linked peptides, SPACX allows comprehensive analysis of the protein interactome within living cells. Leveraging structure refinement with cross-linking restraints, we identify subcellular-specific conformation heterogeneity of PTEN, revealing dynamic differences in its dual specificity domains between the nucleus and cytoplasm. Furthermore, by discerning conformational disparities, we identify 83 cytoplasm-exclusive and 109 nucleus-exclusive PTEN-interacting proteins, each associated with distinct biological functions. Upon induction of ubiquitin-proteasome system stress, we observe dynamic alterations in PTEN assembly and its interacting partners during translocation. These changes, including the identification of components and interaction sites, are characterized using the SPACX approach. Notably, SPACX enables identification of unique interacting proteins specific to PTEN isoforms, including PTEN and PTEN-Long, through the determination of sequence-specific cross-linking interfaces. These findings underscore the potential of SPACX to elucidate the functional diversity of proteins within distinct subcellular sociology.

Effect of phase composition on the crystal structure and microwave dielectric properties of ZnMg2TiO5 ceramics

Novel microwave dielectric ceramics ZnMg2TiO5 were synthesized by traditional solid-state method. Crystal structure refinement, transmission electron microscopy (TEM), and Raman spectroscopy reveal the coexistence of a secondary phase, MgO, with the predominant cubic spinel phase (Fd-3m) in ZnMg2TiO5 ceramics. The ceramics with dense microstructures exhibit excellent microwave dielectric properties at 1260 °C: εr = 15.6, Q×f = 92,899GHz (at 10.8GHz), and τf = −56.9 ppm/°C. The content of MgO, driven by thermodynamic factors, influences significantly impact the microstructure and microwave dielectric properties of the ceramics, particularly inducing the generation of localized lattice distortions and the formation of dislocations. The εr follows the same trend as the molecular polarizability of the actual individual crystal cells. Notably, a near-zero τf (−7.4 ppm/°C) was realized by two-phase composites and excellent comprehensive properties were obtained (εr = 17.9, Q×f = 57,546GHz).