CERAMICS INTERNATIONAL
·
2024
·
IF 5.1
Xinyang Wen,Huaicheng Xiang,Xin Mo,Qingfeng Li,Ying Tang,Liang Fang
To explore the effect of B-site ion variation in the garnet structure on the microwave dielectric properties, we introduced part of Y 3+ into Y 3 Ga 5 O 12 to form a series of Y 3 (Y x Ga 2- x )Ga 3 O 12 ( x = 0–0.9) ceramics. Rietveld refinements, based on the XRD data, reveal that the Y 3+ x Ga 5- x O 12 ( x = 0–0.8) ceramics crystallized in the garnet structure with the Ia -3 d space group, and two phases simultaneously coexisted in the x = 0.9 ceramics. The average B-site cations were compressed, A-site cations exhibited rattling, and the overall structure of Y 3+ x Ga 5- x O 12 ( x = 0–0.8) slightly expanded. As the concentration of Y 3+ at the B-site increased in pure-phase ceramics, the ε r (12.15–12.79) and τ f (−69.95 ∼ −60.72 ppm/°C) exhibited an upward trend, while the Q × f descended (101,902–79,209 GHz). The factors influencing the microwave dielectric properties were further examined by considering the ionic polarizability, bond valence, lattice energy, and packing fraction.
研究领域:
材料科学
·
物理学
✓ 已验证
DOI
高影响因子
MATERIALS RESEARCH BULLETIN
·
2024
·
IF 5.3
Kang Du,Zheyu Liu,Changzhi Yin,Yiyang Cai,Mengdie Zhou,Tailai Wen,Wei Zhu,Cai Zhou,Weijia Han,Shengxiang Wang,Wen Lei
Novel Ba 2 RE 2 Si 4 O 13 ( RE = La, Nd, Sm, Eu, Gd, Ho, Er and Yb) ceramics were prepared by traditional solid reaction methods. The phase compositions of Ba 2 RE 2 Si 4 O 13 ceramics were explored. The triclinic structure with P 1 ¯ space group of Ba 2 RE 2 Si 4 O 13 ceramics was confirmed by TEM and Rietveld refinement analyses, and the decrease in the ionic radius of RE 3+ induced the phase transition from low symmetry (triclinic) to high symmetry (monoclinic) between Ba 2 Sm 2 Si 4 O 13 and Ba 2 Eu 2 Si 4 O 13 . ε r-exp of the Ba 2 RE 2 Si 4 O 13 ceramics was significantly affected by ionic polarisability. The ‘rattling and compressing effects’ of cations also affected the ε r-exp of Ba 2 RE 2 Si 4 O 13 ceramics. The intrinsic dielectric loss of Ba 2 RE 2 Si 4 O 13 ceramics were evaluated by the far-IR reflectivity spectrum, and high Q × f values of the Ba 2 Nd 2 Si 4 O 13 and Ba 2 Eu 2 Si 4 O 13 ceramics were attributed to their large total lattice energy and activation energy. The average bond valence of RE 3+ played an important role in controlling the τ f values of the Ba 2 RE 2 Si 4 O 13 single-phase ceramics, and the high average bond valence of RE 3+ corresponded with the small negative τ f values. Great microwave dielectric properties ( ε r = 11.52, Q × f = 33,600 GHz at 11.80 GHz and τ f = ‒25.6 ppm/ °C) were obtained in the Ba 2 Nd 2 Si 4 O 13 single-phase ceramic.
研究领域:
材料科学
·
物理学
✓ 已验证
DOI
高影响因子
JOURNAL OF ALLOYS AND COMPOUNDS
·
2023
·
IF 6.2
Haotian Xie,Ying Tang,Yang Yang,Ning Zhang,Xiaolong Gu,Huaicheng Xiang
In microwave dielectric materials , the phenomenon that the measured permittivity ( ε r ) is inconsistent with the calculated permittivity ( ε r (C-M) ) often occurs. In the present work, the intrinsic factors affecting the microwave dielectric properties of Ga-based garnet Ca 3 B 1.5 Ga 3.5 O 12 (B = Nb, Ta) are studied by bond valence and the Phillips-Van Vechten-Levine (P-V-L) methods, and the relationship between lattice-induced strain effect and dielectric polarization is elucidated. Since the ionic polarizability of Nb 5+ is lower than that of Ta 5+ , the ε r (C-M) values of Ca 3 Nb 1.5 Ga 3.5 O 12 (CNG) and Ca 3 Ta 1.5 Ga 3.5 O 12 (CTG) are 11.06 and 12.17, respectively. However, this is the opposite trend of the measured values (15.00 and 12.62). The global instability index ( GII ) is equal to 0.013 and 0.044 v.u. , respectively. Both the indexes, bond strain index ( BSI ) and GII , are related to the entire crystal structure. A stronger lattice-induced compressive strain and a higher degree of covalency lead to a lower measured ε r , a higher Q×f , a higher temperature coefficient of permittivity τ ε , and a larger negative τ f .
研究领域:
材料科学
·
物理学
✓ 已验证
DOI
高影响因子
CERAMICS INTERNATIONAL
·
2025
·
IF 5.6
Wenlong Tao,Congxue Su,Yan Wang,Huini Mo,Jun Fan,Yuan Sun,Shuping Tang,Huanfu Zhou,Xingliu Qin,Huidan Lu
The exploration of high-performance microwave dielectric ceramics exhibiting low-permittivity is of great significance for the advancement of next-generation wireless communication technologies. To meet the demands of the growing field of wireless communication, two novel low-permittivity KBaLnMo 3 O 12 (Ln = Eu, Yb; named KBEM and KBYM) ceramics with monoclinic structure were synthesized using a solid-state reaction route. Good microwave dielectric properties of ε r = 8.54, Q × f = 30, 611 GHz, and τ f = −45.2 ppm/°C were achieved for KBEM sintered at 790 °C, and KBYM sintered at 810 °C possessed excellent microwave dielectric properties of ε r = 8.87, Q × f = 52, 241 GHz, and τ f = −34.9 ppm/°C. According to the bond valence result, K + and Ba 2+ presented a strong compressed state but most Mo 6+ exhibited a slightly rattling state in both ceramics. The higher packing fraction and lattice energy might be the main reason for the higher Q × f in KBYM. The Mo–O bond in both ceramics played a vital role in influencing the Q × f according to the Phillips−Van Vechten−Levine (P−V−L) theory. Furthermore, KBaLnMo 3 O 12 (Ln = Eu, Yb) ceramics show good chemical compatibility with Ag powders and are suitable for low temperature co-fired ceramic (LTCC) applications.
研究领域:
材料科学
·
无机化学
·
电子器件
✓ 已验证
产品关联
DOI
高影响因子
Materials Today Communications
·
2022
·
IF 3.662
Shuangfeng Wu,Chunchun Li,Huina Wei,Xingping Song,Laijun Liu,Jungu Xu
The tetragonal LiNbWO 6 (α−LiNbWO 6 ) with a trirutile structure was previously reported to have good lithium ion conductivity. However, the electrical properties of the hexagonal LiNbWO 6 (β−LiNbWO 6 hereafter) polymorph have not been reported yet mainly due to the difficulty to obtain single-phase. Herein, by quenching the sample from high temperature to room temperature at ambient air condition, a series of pure-phase β−LiNb 1- x Ta x WO 6 ( x = 0, 0.05, 0.1) materials were successfully prepared. The phase evolutions and conductivities of these materials were investigated by variable temperature X-ray diffraction and alternating current impedance spectroscopy techniques, respectively. The results revealed that lithium ion conduction also dominated in this hexagonal polymorph of LiNbWO 6 and an interesting great ionic conduction enhancement behavior was observed at a temperature region of 660–800 °C due to the minor phase transition from hexagonal to tetragonal. In addition, the possible ionic conducting mechanisms in both the tetragonal and hexagonal LiNbWO 6 materials were studied by the bond-valence-based method for the first time. The results disclosed two-dimensional and three-dimensional lithium ion migration pathways for the tetragonal and hexagonal LiNbWO 6 , respectively.
研究领域:
材料科学
·
电化学
·
固体化学
✓ 已验证
DOI
高影响因子
ADVANCED FUNCTIONAL MATERIALS
·
2025
·
IF 19
Lei Gao,Zhigang Zhang,Zheyuan Zhang,Yongrui Luo,Bolong Hong,Longbang Di,Haijin Ni,Jinlong Zhu,Ruqiang Zou,Enyue Zhao,Songbai Han
The halide solid-state electrolyte (SSE) Li 2 ZrCl 6 has emerged as a promising candidate for all-solid-state batteries (ASSBs) due to the abundance of Zr in the Earth's crust and its low cost. However, its relatively low ionic conductivity prevents it from meeting the essential performance threshold (> 1 mS cm −1 ) required for application in ASSBs. In this work, a novel strategy is presented to enhance ionic conductivity by incorporating high-valence Ta 5+ into the Li 2 ZrCl 6 framework, resulting in a series of Li-deficient Li 2– x Ta x Zr 1– x Cl 6 (LTZC, 0 ≤ x ≤ 0.4) SSEs. Remarkably, the LTZC ( x = 0.275) achieves a high ionic conductivity of 1.43 mS cm −1 at 30 °C, surpassing that of Li-rich Li 2 ZrCl 6 -based SSEs (e.g., Li 2+2 x Zr 1– x Mg x Cl 6 ). Neutron powder diffraction reveals a pronounced rearrangement of Li + ions upon Ta 5+ doping, and bond-valence site energy calculations indicate that this rearrangement enhances Li + transport within the lattice. Furthermore, ASSBs incorporating LTZC SSE with LiCoO 2 or LiNi 0.8 Co 0.1 Mn 0.1 O 2 cathode and Li-In anode exhibit excellent cycling performance. This work underscores the effectiveness of structural regulation in developing Li-deficient halide SSEs as a viable strategy for enhancing their electrochemical performance.
研究领域:
材料科学
·
电化学
·
储能
·
固态离子学
✓ 已验证
产品关联
DOI
高影响因子
Energy Storage Materials
·
2018
·
IF 0
Gaozhan Liu,Dongjiu Xie,Xuelong Wang,Xiayin Yao,Shaojie Chen,Ruijuan Xiao,Hong Li,Xiaoxiong Xu
A series of new solid electrolytes of Li 3+3 x P 1- x Zn x S 4- x O x ( x = 0.01, 0.02, 0.03, 0.04, 0.05, 0.06) are synthesized successfully via Zn, O co-doping the Li 3 PS 4 glass-ceramic for the first time. The result shows that Li 3 PS 4 aliovalent substitution of 2 mol% ZnO (Li 3.06 P 0.98 Zn 0.02 S 3.98 O 0.02 ) presents the highest conductivity of 1.12×10 −3 S cm −1 at room temperature, which is twice that of the pristine Li 3 PS 4 . Besides, Li 3.06 P 0.98 Zn 0.02 S 3.98 O 0.02 exhibits excellent stability against humid air , lithium metal and chlorobenzene solvent. The mechanisms of the enhancement of conductivity and air-stability are well understood by conducting first-principles density functional theory (DFT) calculation and Bond-Valence (BV) analysis, and the results well demonstrate that the conductivity and air-stability of Li 3 PS 4 could be improved via Zn, O dual-doping, in which partial P 5+ could be substituted by Zn 2+ , and a part of S 2- could be replaced by O 2- . Finally, the all-solid-state lithium battery (ASSLB) with bi-layer electrolytes of LiCoO 2 /Li 10 GeP 2 S 12 /Li 3.06 P 0.98 Zn 0.02 S 3.98 O 0.02 /Li is assembled, and it delivers an initial discharge capacity of 139.1 mAh g −1 at 0.1 C and a capacity retention of 81.0% after 100 cycles at room temperature. This work combines systematical experimental characterizations and sufficient theoretical calculations to develop a new promising sulfide electrolyte with superior lithium ion conductivity and high air-stability for ASSLBs application.
研究领域:
材料科学
·
电化学
·
能源存储
✓ 已验证
产品关联
DOI
JOURNAL OF PHYSICS D-APPLIED PHYSICS
·
2023
·Vol. 57
·期 1
·015301
·
IF 3.4
Xiao Zhang,Zhe Xiong,Bin Tang,Chengtao Yang
The rapid advancement of mobile communications technology is imposing greater demands on electronic components. Microwave dielectric ceramics with a high dielectric constant (r) are crucial for the miniaturization and integration of microwave devices. Herein, The perovskite-structured (Ca0.61Nd0.26)1−x(Li0.5Nd0.5)xTiO3 (0 ⩽ x ⩽ 0.8) microwave dielectric ceramics with high r value were prepared by solid-state reaction method. The results demonstrated that the r value reached its peak at x = 0.6, which was influenced by the bond valence at B-sites. The τf and Q× f values decreased with increasing x value. Doping (Li0.5Nd0.5)2+ at A-sites led to an increase in the full width at half maximum of Raman peaks, indicating higher internal loss. A high dielectric constant and temperature-stable (Ca0.61Nd0.26)0.27(Li0.5Nd0.5)0.73TiO3 ceramic can be sintered with good microwave dielectric properties of r = 129.4, Q× f= 2,787 GHz, and τf = +1.9 ppm/°C.
研究领域:
材料科学
·
电气工程
·
微波技术
·
陶瓷
✓ 已验证
DOI
高影响因子
JOURNAL OF SOLID STATE CHEMISTRY
·
2021
·
IF 3.498
Fang Wang,Xiao-Ni Yao,Yao Guo,Liguo Yang,Yi-Gang Chen,Xian-Ming Zhang
Two new metal aluminium phosphate millimetre-crystals NaBa 2 Al(P 2 O 7 ) 2 and NaBaAl(PO 4 ) 2 were successfully grown by using high-temperature molten method. The crystals NaBa 2 Al(P 2 O 7 ) 2 and NaBaAl(PO 4 ) 2 are located in space groups P ¯1 and P 2 1 /c, respectively. NaBa 2 Al(P 2 O 7 ) 2 displays a [Al(P 2 O 7 ) 2 ] 1D chain structure constructed from corner-sharing linkage of novel AlP 4 O 16 9− anion groups, and the AlP 4 O 16 9− group is formed by edge-sharing connection of two P 2 O 7 dimers and one AlO 6 octahedron . However, NaBaAl(PO 4 ) 2 exhibits a new [Al(PO 4 ) 2 ] 2D layer structure composed of AlP 2 O 10 7− anion groups via corner-sharing, and the AlP 2 O 10 7− group is generated by alternate linkages of corner-sharing PO 4 and AlO 4 tetrahedra. Analysis based on Pauling's electrostatic rule and Brown's bond valence model finds that structural feature of the two anion groups is mainly responsible for their different dimension structures in addition to structure-directed role of large Ba 2+ . The two crystals manifest a deep-UV optical transparency below 190 nm and good thermal stability, making them a potential optical window material. First-principles calculations reveal that the optical bandgaps of both crystals are determined by the Ba–O groups, rather than Al–O and P–O common groups.
研究领域:
材料科学
·
光学
·
晶体学
✓ 已验证
产品关联
DOI
高影响因子
Energy Storage Materials
·
2024
·
IF 18.9
Kang-Ning Gao,Fan Bai,Zhuang Sun,Tao Zhang
Halide solid electrolytes , known for their stability to 4 V-class cathodes and deformability, emerge as promising candidates for high-performance all-solid-state batteries. Unfortunately, their synthesis often involves expensive elements, limiting mass production and cost-effectiveness. In this study, aliovalent-substituted Li 2 ZrCl 6 with Al 3+ is fabricated by one-step ball milling , exhibiting lower cost, higher ionic conductivity and a wider electrochemical window. The cost is reduced by approximately 13.4 % through a 25 % aliovalent substitution. Li + conductivity of Li 2+x Zr 1-x Al x Cl 6 increases from 0.12 mS/cm ( x = 0) to a peak of 1.13 mS/cm ( x = 0.25) at 25 °C, and activation energy (Ea) reduces from 0.43 eV to 0.29 eV, which is attributed to the extension of Li + migration pathways along intra- and inter- ab-plane around Al sites as revealed by AIMD and BVSE calculations. Both experimental result and calculation indicate that the substitution of Al 3+ improves the oxidation potential from 4.1 V in Li 2 ZrCl 6 to 4.3 V in Li 2.25 Zr 0.75 Al 0.25 Cl 6 . Furthermore, the excellent electrochemical performance of all-solid-state batteries is demonstrated using Al 3+ -substituted Li 2 ZrCl 6 and commercial LiNi 0.8 Co 0.1 Mn 0.1 O 2 . The unravelled multifaceted effects of Al 3+ aliovalent substitution in Li 2 ZrCl 6 solid electrolyte endow it highly advantageous for future applications in halide-based all-solid-state lithium batteries.
研究领域:
材料科学
·
电化学
·
储能技术
·
固态化学
·
电池技术
✓ 已验证
DOI
高影响因子
CHEMICAL RESEARCH IN CHINESE UNIVERSITIES
·
2025
·Vol. 41
·期 2
·296-304
·
IF 3
Sun Huangyijia,Li Xiaohui,Zeng Xiaoling,Liu Jian,Rakhmatullin Aydar,Lou Chenjie,Tang Mingxue,Fernández-Carrión Alberto Jose,Kuang Xiaojun
Sodium-ion conducting materials in sodium-ion battery have drawn widespread attention in energy storage technologies due to the advantages of low cost, high performance, and efficient environmental adaptability. Herein, bond valence site energy (BVSE) calculations were used to predict the sodium ion electrical performances by the Na nonstoichiometric modifications, and we have carried out fine experiments to modulate the sodium ion conductivity of Na x Zn 2 TeO 6 guided by BVSE calculations. The optimized composition Na 2.1 Zn 2 TeO 6 shows the superior sodium ionic conductivity of 5.3×10 −3 S/cm at 190 °C, with a low activation energy of 0.28 eV. The excess Na preferentially occupies the Na1 site with tetrahedral voids, which has a higher capacity for sodium ion migration, as revealed by the combined neutron powder diffraction technique with the 1D and 2D 23 Na solid-state NMR technique, which is responsible for the variations in sodium ion conductivity. In addition, it is worth noting that the resulting Na 2.1 Zn 2 TeO 6 material maintains superior thermal and phase stability, as well as approximately the same thermal expansion coefficient values even during the temperature rise and fall cycles in the temperature range of 25–800 °C. Furthermore, molecular dynamics simulations revealed that the sodium ions exhibit longrange anisotropic migration within the Na + interlayers of Na 2.1 Zn 2 TeO 6 .
研究领域:
材料科学
·
储能技术
·
固体离子学
·
电池技术
·
计算材料化学
✓ 已验证
产品关联
DOI
高影响因子
CERAMICS INTERNATIONAL
·
2025
·Vol. 51
·期 21
·34195-34202
·
IF 5.6
Zelai Cheng,Xi wang,Mingshan Qu,Xiuling Yang,Xian Jian,Hua Su
With the advent of fifth-generation technology, high-performance microwave dielectric materials with low dielectric constant are urgently needed to enable the miniaturization and integration of communication devices. This study presents the synthesis and characterization of a composite comprising SrCu 0.95 Mn 0.05 Si 4 O 10 (SCSMn) and Ba 3 V 2 O 8 (BV) ceramics, designed for LTCC applications. In a solid-state reaction method, the composition of the synthesized composite was tailored to adjust the τ f value and lower the sintering temperature . The results indicate that the composition of 47.5 wt% SCSMn and 52.5 wt% BV sintered at 925 °C exhibits optimal microwave dielectric properties , including ε r of 8.86, a Q × f of 33860 GHz, and a τ f of 3 ppm/°C. Microstructural analysis revealed that interionic diffusion during sintering induced amorphous phase formation and an increased concentration of defect-associated Cu + and V 5+ species. Concomitant modifications in bond valence summation (BVS) parameters and global instability index (GII) values within the composite ceramics were observed, which collectively account for the discrepancies between theoretical predictions and experimental dielectric properties . The composite material also demonstrated excellent impedance matching and radiation performance when utilized as a substrate for simulating a slot-coupled antenna, validating its promising potential for LTCC applications .
研究领域:
材料科学
·
微波工程
·
陶瓷与复合材料
·
电子材料
·
低温共烧陶瓷(LTCC)
✓ 已验证
产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）