International Journal of Applied Ceramic Technology
·
2025
·
IF 2.3
Bixian Zhang,Kai Yang,Zhuohang Li,Sihao Jian,Bei Ren,Ziqian Meng,Yinghui Tang,Yang Miao
Yttrium iron garnet (YIG) ferrite is extensively utilized in microwave devices due to its exceptional fundamental electromagnetic properties and easily adjustable magnetic properties. In recent years, there has been a growing interest in investigating high-entropy garnets. However, its dielectric properties have not been extensively studied. This study prepared a series of bismuth-containing high-entropy yttrium iron garnet ferrites (Bi 0.6 Gd 0.6 Ho 0.6 Y 0.6 Re 0.6 ) Fe 5 O 12 (Re = Dy, Er, Tm, Yb) using the solid-phase reaction method. The addition of Bi 3+ to the high-entropy matrix resulted in a reduction of the optimal phase forming temperature of garnet from 1450°C to 1150°C. Despite the incorporation of Bi 3+ with a relatively large ionic radius, no heterophase generation occurred, leading to the formation of a single garnet phase. These high-entropy garnet samples exhibited unique magnetic properties along with high dielectric constants and low dielectric losses. Specifically, the dielectric constant (ε') of sample HEYIG-4 is measured at 20.26, with a low dielectric loss of just 2.78 × 10 −3 , while the specific saturation magnetization reached 16.86 emu/g. This paper expanded research within the field of high-entropy garnet ferrites.
研究领域:
材料科学
·
物理学
✓ 已验证
产品关联
DOI
高影响因子
CERAMICS INTERNATIONAL
·
2023
·
IF 5.2
Shengtai Zhang,Zhen Teng,Linzhen Wu,Chen Chen,Yongqiang Tan,Xiaosong Zhou
Spark plasma sintering (SPS) is a fast and efficient method for preparing functional ceramics . This article investigates the phase evolution, thermal expansion and chemical stability of traditional (Y 1.2 Nd 1.8 Fe 5 O 12 ) and high-entropy ((Y, Gd, Sm, Eu, Dy) 3 Fe 5 O 12 ) garnet ceramics. Prepared under conventional SPS (50 MPa) conditions at 900–1100 °C. The results indicate that using SPS sintering method can significantly reduce the sintering temperature (1100 °C) and time (3 min) of garnet ceramics. (Y, Gd, Sm, Eu, Dy) 3 Fe 5 O 12 (1.6 × 10 −6 K −1 ) exhibits superior thermal expansion stability compared to Y 1.2 Nd 1.8 Fe 5 O 12 (5.4 × 10 −6 K −1 ). The strong REE-O bond energy and severe lattice distortion of high entropy garnet ceramics hinder the migration and diffusion of cations, resulting in higher leaching resistance of high-entropy garnet ceramics (∼10 −7 g m −2 d −1 -10 −8 g m −2 d −1 ) compared to traditional garnet ceramics (∼10 −5 g m −2 d −1 -10 −6 g m −2 d −1 ). Therefore, SPS has broad application prospects in the low-temperature preparation of high-entropy garnet ceramics for immobilization of actinide elements.
研究领域:
材料科学
·
陶瓷工程
·
核废料处理
✓ 已验证
DOI
高影响因子
PHYSICA B-CONDENSED MATTER
·
2021
·
IF 2.436
Fenhong Liu,Xiaojun Tan,Shoulei Xu,Xiangyu Wang,Bernard A. Goodman,Wen Deng
Thulium-doped yttrium aluminum garnet (YAG) single crystals with composition (Tm x Y (1- x ) ) 3 Al 5 O 12 (x = 0.001–0.02) were prepared by the optical floating zone method. The crystals were of high quality with no cracks, bubbles, or inclusions, and with >80% visible light transmittance . The lowest value for the mean positron lifetime was observed with crystals which had x = 0.01, which demonstrates that this composition had the fewest number of defects. This sample also produced the highest emission intensities in the PL spectra, and had narrower lines than those previously reported for Tm 3+ -doped yttria-stabilized zirconia. However, with higher Tm 3+ concentrations, interactions between neighboring Tm 3+ ions resulted in partial quenching of the luminescence. Overall, Tm-doped YAG single crystals synthesized by the optical floating zone (OFZ) method contained few defect centers and exhibited narrow luminescence linewidths , which demonstrate potential uses in high resolution applications.
研究领域:
材料科学
·
光学
✓ 已验证
产品关联
DOI
高影响因子
Nanomaterials
·
2019
·Vol. 9
·期 5
·721
·
IF 4.034
Zhencai Dong,Chao Xu,Yongmin Wu,Weiping Tang,Shufeng Song,Jianyao Yao,Zhengyong Huang,Zhaoyin Wen,Li Lu,Ning Hu
Garnet Li7La3Zr2O12is one of the most promising solid electrolytes used for solid-state lithium batteries. However, low ionic conductivity impedes its application. Herein, we report Ta-doping garnets with compositions of Li7-xLa3Zr2-xTaxO12(0.1 ≤ x ≤ 0.75) obtained by solid-state reaction and free sintering, which was facilitated by graphene oxide (GO). Furthermore, to optimize Li6.6La3Zr1.6Ta0.4O12, Mg2+was select as a second dopant. The dual substitution of Ta5+for Zr4+and Mg2+for Li+with a composition of Li6.5Mg0.05La3Zr1.6Ta0.4O12showed an enhanced total ionic conductivity of 6.1 × 10−4S cm−1at room temperature. Additionally, spark plasma sintering (SPS) was applied to further densify the garnets and enhance their ionic conductivities. Both SPS specimens present higher conductivities than those produced by the conventional free sintering. At room temperature, the highest ionic conductivity of Li6.5Mg0.05La3Zr1.6Ta0.4O12sintered at 1000 °C is 8.8 × 10−4S cm−1, and that of Li6.6La3Zr1.6Ta0.4O12sintered at 1050 °C is 1.18 × 10−3S cm−1.Keywords:garnet;dual substitution;spark plasma sintering;conductivity
研究领域:
材料科学
·
电化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF THE AMERICAN CERAMIC SOCIETY
·
2023
·Vol. 106
·期 11
·7009-7018
·
IF 3.9
Yong Ge,Baoliang Xu,Yiliao Liao,Xueyu Zhang,Xu Yan,Caohui Zheng,Tao Duan
Multiphase ceramics have a high application potential in the field of nuclear waste immobilization because of the efficient synergy between the individual phases. In this work, zirconia/garnet multiphase ceramics with high efficient and effective immobilization capacity of trivalent actinides were successfully prepared using conventional solid-phase sintering. ZrO 2 doping increases the lattice site available for nuclide substitution and advance the immobilization capacity of the ceramic substrate for nuclide. At the same time, the phase change of zirconia is used to tougher and improve the physical properties of the ceramic waste form. The feasibility of using multiphase ceramics for the efficient immobilization of trivalent actinides was assessed by studying the phase evolution, microstructure, Vickers hardness, and chemical stability of the multi-phase ceramics. Zr 1- x Nd x O 2- x /2 /Ca 3- y Nd y Zr 3- y Fe y -1 Fe 3 O 12 multiphase ceramics exhibited superior physical or chemical properties compared to most of the multiphase ceramics as well as the previously prepared single-phase calcium garnet ceramic waste forms. The Vickers hardness of all the multiphase ceramic samples ranged between 685 and 730 HV0.5. Under the condition of using simulate Bei Shan groundwater as leaching agent, the normalized leaching rates of Nd is approximately 10 − 6 g · m −2 · day −1 , showing good chemical stability and achieving efficient and effective immobilization of trivalent actinides. The excellent chemical, as well as physical properties of Zr 1- x Nd x O 2- x /2 /Ca 3- y Nd y Zr 3- y Fe y -1 Fe 3 O 12 multiphase ceramics are expected to make them one of the substrates for more efficient and effective immobilizing of trivalent actinides.
研究领域:
材料科学
·
核废料管理
✓ 已验证
DOI
高影响因子
Frontiers of Materials Science
·
2015
·Vol. 9
·期 4
·366-372
·
IF 1
Xia Yu,Ma Liang,Lu Hui,Wang Xian-Ping,Gao Yun-Xia,Liu Wang,Zhuang Zong,Guo Li-Jun,Fang Qian-Feng
Garnet-like Li 6.8 La 3 Zr 1.8 Bi 0.2 O 12 (LLZBO) + x mol.% Al 2 O 3 ( x = 0, 1.25, 2.50) lithium ionic electrolytes were prepared by conventional solid state reaction method under two different sintering temperatures of 1000°C and 1100°C. XPS, induced coupled plasma optical emission spectrometer (ICP-OES), XRD and AC impedance spectroscopy were applied to investigate the bismuth valance, lithium concentration, phase structure and lithium ionic conductivity, respectively. Electrical measurement demonstrated that ionic conductivity of Al-added LLZBO compounds could be obviously improved when the sample sintering temperature increased from 1000°C to 1100°C. The highest ionic conductivity 6.3×10 -5 S/cm was obtained in the LLZBO-1.25%Al sample sintered at 1100°C, in consistent with the lowest activation energy 0.45 eV for the lithium ion migration. The mechanism related with good ionic conductivity in the Al-added LLZBO sample was attributed to the lattice distortion induced by the partial Al substitution at Zr sites, which is helpful to improve the migration ability of Li ions in lattice.
研究领域:
材料科学
·
电化学
✓ 已验证
DOI
高影响因子
SOLID STATE IONICS
·
2019
·
IF 2.886
Daoguang Zheng,Jianfeng Zhang,Qin Wang,Xingxing Pan,Jianxin Wang,Wanbing Guan,Jun Yang
Polycrystalline cubic Li 6.5 Al 0.22 La 3 Zr 1.93 O 11.94 (LLZO) with garnet structure has been synthesized by solid-liquid method (SLM) with acrylic acid as organic complexing agent , and acetate sol coated nano-ZrO 2 powders as template. The polymeric precursors are characterized by means of TG/DTA, the resultant powders and sintered LLZO pellets are characterized by ICP-OES, X-ray diffraction (XRD), scanning electron microscopy (SEM) and impedance spectroscopy . It is shown that the morphology of the powders is dependent on the preparation conditions such as molar ratio of acrylic acid to metallic ions (L/M) and the pH values. Prepared powders are purity, single phase, an ellipsoidal shape and a particle size of 2–4 μm with good neck connection. The ionic conductivity of sintered LLZO pellets at 1100 °C for 6 h at room temperature is 3.09 × 10 − 4 S cm − 1 and the relative density is 94.1%. The solid-liquid method can lower the sintering temperature , greatly shortens holding time, and gets relatively good the ionic conductivity and it is suitable for mass synthesis of high performance LLZO powders with the advantages of less amount of organic reagent and friendly environment.
研究领域:
材料科学
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
DALTON TRANSACTIONS
·
2021
·Vol. 51
·期 2
·645-654
·
IF 4.39
Qinghong Meng,Guoying Zhao,Qi Zhu,Xiaodong Li,Xudong Sun,Ji-Guang Li
Synergistic doping of the metastable Gd3Al5O12:Ce garnet with a Ca2+/Hf4+ pair and Sc3+ to form Gd2.97−xCaxHfxScyAl3O12:0.03Ce (x = 0.5–2.0, y = 0.0–1.5, x + y = 2.0) solid solution was conducted for the structural stabilization and photoluminescence manipulation. The site selection of Ca2+/Hf4+/Sc3+ dopants and the effects of doping on the crystal structure, local coordination, band structure and Ce3+ luminescence were revealed in detail with the results of XRD, Rietveld refinement, TEM, and UV-Vis/photoluminescence spectroscopy. A decrease in Ca2+/Hf4+ and an increase in the Sc3+ content were observed to shrink the lattice, widen the bandgap of the garnet host, red-shift the excitation/emission wavelength, broaden the emission band and shorten the fluorescence lifetime of Ce3+. The spectral changes were rationalized by considering the local coordination and crystal field splitting of the Ce3+ 5d energy level. Application of typical Gd0.97Ca2Hf2Al3O12:0.03Ce (x = 2.0, y = 0) cyan and Gd2.47Ca0.5Hf0.5Sc1.5Al3O12:0.03Ce (x = 0.5, y = 1.5) greenish-yellow phosphors in w-WLED lighting produced low correlated color temperatures of ∼3842 and 3514 K, high color rendering indices of ∼88 and 93 and favorable luminous efficacies of ∼32.9 and 14.7 lm/W under the excitation of 395 nm n-UV and 450 nm blue LED chips, respectively.
研究领域:
材料科学
·
光学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
SOLID STATE IONICS
·
2020
·
IF 3.107
Xuefeng Shen,Qian Zhang,Tianxiang Ning,Jianlei Liu,Taoyong Liu,Zhiwei Luo,Yao He,Chunchun Qin,Anxian Lu
Garnet solid electrolyte is the most promising candidate among inorganic solid electrolytes due to its wide potential window, good compatibility and high safety. In this work, a dual doping strategy is offered for the development of garnet-type electrolytes with high ionic conductivity . Te 6+ is introduced into the Zr sites to stabilize the high-ionic conductivity cubic phase. Simultaneously, Sr 2+ enter the La sites to achieve a fine-tuning of the Li + concentration by charge compensation, acting as a sintering agent of Te 6+ /Sr 2+ doped electrolytes. The structure, chemical composition and ionic conductivity of Li 7 − 2 y + x La 3 − x Sr x Zr 2 − y Te y O 12 ( x = 0–0.25, and y = 0.35) electrolytes are systematically investigated by X-ray diffraction, Raman spectroscopy , scanning electron microscope , Energy Dispersive X-ray Spectroscopy, Inductively Coupled Plasma-Optical Emission Spectrometry and Alternating Current impedance. The results show that the optimal amount of Sr 2+ substitution helps to reduce the total resistance by promoting the growth of grains and ceramic densification . Among the investigated compositions, the composition with Li 6.425 La 2.875 Sr 0.125 Zr 1.65 Te 0.35 O 12 exhibits excellent performance with relative density of 97.95%, conductivity of 4.27 × 10 −4 S cm −1 at 25 °C and activation energy of 0.30 eV. The assembled Li/Li 6.425 La 2.875 Sr 0.125 Zr 1.65 Te 0.35 O 12 /Li symmetrical batteries are cycled galvanostatically under different current densities. The results show that the symmetrical battery can achieve good cyclic stability, good Li + stripping and plating process and low overpotential.
研究领域:
材料科学
·
电化学
✓ 已验证
DOI
高影响因子
JOURNAL OF ELECTRONIC MATERIALS
·
2022
·Vol. 51
·期 3
·1180-1188
·
IF 2.047
Ji Xinran,Zhou Ke,Zhao Ye,Sun Meiling,Dong Shijun,Zhang Hongbo,Cao Hechun,Zheng Hui,Wu Qiong,Zhang Yang
The regulation of magnetic and dielectric properties for yttrium iron garnet ferrites by ion doping is highly desirable in microwave devices. In this work, yttrium iron garnet ferrites co-doped with Pr-Zn-Zr atoms with the chemical formula Pr x Y 3-x Zn 0.1 Zr 0.1 Fe 4.8 O 12 (x = 0, 0.1, 0.15, and 0.2) were prepared. The dependence of the crystal structure, microstructure, magnetic, and dielectric properties of the obtained samples on the Pr doping concentration was investigated. The morphologies and crystal structure characterizations confirm that the Pr ion has effectively doped in the yttrium iron garnet ferrites and increased the lattice parameter and grain size. The magnetic characterization shows that the saturation magnetization also increases with the Pr concentration and obtains a maximum value of 27.68 emu/g at x = 0.15. Additionally, the doping of Pr increases the magnetic anisotropy constant K 1 which increases ferromagnetic resonance linewidth. Lastly, the dielectric properties measurement further indicates that Pr doping improves both real and imaginary parts of permittivity, and the highest value of the real part of the permittivity is obtained at x = 0.15. Consequently, the crystal structure, microstructure, magnetic properties, and dielectric properties of garnet ferrite can be effectively regulated by the Pr doping concentration, and excellent properties of the ceramic can be obtained at x = 0.15, which allows potential applications in microwave devices.
研究领域:
材料科学
·
物理学
✓ 已验证
DOI
高影响因子
CRYSTENGCOMM
·
2018
·Vol. 20
·期 48
·7773-7781
·
IF 3.304
Rui Yuan,Xi-Xi Xie,Li-Xian Zheng,Li-Li Yu,Jian-Feng Hu,Hai-Ming Qin,Zhi-Jun Zhang,Jing-Tai Zhao
By exploring the optimal reaction temperature and the ratio of Na2SO4 to the precursor, highly symmetrical rhombic dodecahedral yttrium aluminum garnet (Y3Al5O12, YAG) microcrystals with a good dispersity were successfully prepared using improved hydrothermal methods. YAG microcrystals exhibit well-developed crystal faces, high crystallinity and a controllable crystal size, from hundreds of nanometers to approximately 4 μm. The morphology and crystal size of the YAG microcrystals can be controlled by changing the reaction temperature and the ratio of Na2SO4 to the precursor. After analysis using X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), and energy dispersive spectrometry (EDS), the growth mechanism of the YAG crystals was studied in detail. Cerium doped YAG (YAG:Ce3+) microcrystals exhibit an intense broad band emission at approximately 523 nm. Considering the high crystallinity, controllable size and strong emission of YAG microcrystals, one has reason to assume that they could have wide applications in many areas.
研究领域:
材料科学
·
光学
✓ 已验证
产品关联
DOI
高影响因子
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
·
2016
·
IF 3.205
Yahui Song,Shengnan Wei,Yang Rong,Chunxiao Lu,Yang Chen,Jun Wang,Zhaohong Zhang
Several conduction band co-catalysts (CBCOs), MoO 2 , MoS 2 and MoSe 2 , were prepared to improve the visible-light photocatalytic hydrogen evolution activity of Er 3+ :Y 3 Al 5 O 12 /PdS–ZnS from water splitting, in which the PdS is a valence band co-catalyst (VBCO) used to facilitate the photo-generated hole transfer and the Er 3+ :Y 3 Al 5 O 12 is an up-conversion luminescence agent from visible light to ultraviolet light used to provide the ultraviolet light satisfying the energy demands of wide band-gap ZnS photocatalyst . XRD , SEM, TEM and EDX analyses were employed to confirm the morphology, microstructure and composition of the prepared photocatalysts. UV–vis absorption and PL spectra were also determined to explore luminescence effect of the Er 3+ :Y 3 Al 5 O 12 . The visible-light photocatalytic hydrogen evolution activity of the prepared photocatalysts was evaluated by using Na 2 S and Na 2 SO 3 as sacrificial reagents in aqueous solution under visible light irradiation . The influential factors such as contents of CBCOs (MoO 2 , MoS 2 and MoSe 2 ) and visible-light irradiation time on visible-light photocatalytic hydrogen evolution of Er 3+ :Y 3 Al 5 O 12 /PdS–ZnS–MoX 2 (X = O, S and Se) were investigated in detail. Particularly, Er 3+ :Y 3 Al 5 O 12 /PdS–ZnS–MoSe 2 with 0.30 wt% MoSe 2 shows the highest photocatalytic hydrogen evolution activity.
研究领域:
材料科学
·
能源化学
✓ 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）