JOURNAL OF THE EUROPEAN CERAMIC SOCIETY
·
2020
·
IF 4.495
Zhangyi Huang,Qiuyao Li,Yutong Zhang,Junjing Duan,Haomin Wang,Zhe Tang,Yao Yang,Jianqi Qi,Tiecheng Lu
A nitrate–citrate combustion method combined with microwave sintering was firstly employed for the rapid fabrication of the Gd 2 Zr 2 O 7 matrix immobilizing various amounts of simulated nuclear wastes . Phase evolutions, microstructure changes, element distributions, densification processes and mechanical properties of the as-prepared (1 – x )Gd 2 Zr 2 O 7 · x TRPO (0.0 ≤ x ≤ 0.6) at various temperatures were investigated. Compared to the reported studies, we have increased the immobilization amount of simulated TRPO waste within a crystal structure from 45 to 60 wt%. T d and T g (the threshold temperatures to trigger accelerated densification and grain growth, respectively) were employed to divide the densification process into three stages. the mechanical properties and the densification stages of the (1 – x )Gd 2 Zr 2 O 7 · x TRPO (0.0 ≤ x ≤ 0.6) ceramics sintered under microwave sintering at various temperatures were finally determined. Fine-grained (1 – x )Gd 2 Zr 2 O 7 · x TRPO (0.0 ≤ x ≤ 0.6) ceramic waste forms with average grain size less than 200 nm and relative density higher than 90% can be obtained by microwave sintering at sintering temperature less than 1400 °C.
研究领域:
材料科学
·
核废料管理
✓ 已验证
产品关联
DOI
高影响因子
CERAMICS INTERNATIONAL
·
2017
·
IF 2.986
Zhangyi Huang,Jianqi Qi,Mao Zhou,Yichao Gong,Qiwu Shi,Mao Yang,Wei Han,Zhangkai Cao,Shuting Peng,Tiecheng Lu
A facile solvothermal method has been developed to synthesize Gd 2 Zr 2 O 7 nanopowders with well-controlled particle size and dispersion. The nanopowders were consolidated into dense ceramic pellets by pressureless sintering, and effects of the solvothermal method in microstructure control are demonstrated by comparison with conventional precipitation approach. X-ray diffraction, electron microscopy , gas adsorption, and a standard operating procedure (SOP) in Malvern Instruments were employed to investigate crystallite/grain sizes and structural morphology evolutions of nanopowders and ceramics. Well-crystallized Gd 2 Zr 2 O 7 nanopowders with little agglomeration and narrow size distribution synthesized by this method have an average crystallite size of 3.5 nm and high surface area of 162 m 2 /g. This method also allows the formation of homogeneous and dense Gd 2 Zr 2 O 7 ceramic with bulk density over 94% of the theoretical value achieved after sintering at 1500 °C for 6 h.
研究领域:
材料科学
·
无机非金属材料
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纳米材料化学
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陶瓷学
·
固态化学
✓ 已验证
DOI
高影响因子
JOURNAL OF THE AMERICAN CERAMIC SOCIETY
·
2023
·Vol. 106
·期 11
·7088-7097
·
IF 3.9
Shibing Zuo,Yang He,Yi You,Xiaoyan Shu,Mingfen Wen,Yuexiang Lu,Tao Duan,Jing Chen,Fen Luo,Faqin Dong,Xirui Lu
To extend the practicability of ceramics in immobilizing nuclear waste with fluctuant composition, structural design should be abandoned. The simulated tetravalent actinide waste An 4+ (Ce 4+ ) was directly doped into prepared Gd 2 Zr 2 O 7 , and the waste forms were synthesized by high-temperature solid-state reaction. It has been shown that the maximum loading of CeO 2 in Gd 2 Zr 2 O 7 lies between 20 and 30 wt.%, and Ce elements are uniformly distributed in the matrix. Existing in Ce 3+ and Ce 4+ , cerium ions automatically occupied both the Gd and Zr sites in Gd 2 Zr 2 O 7 according to valence equilibrium. This occupation causes the change of r (A 3+ )/ r (B 4+ ) and eventually leads to the structure transition from pyrochlore to fluorite. In addition, the normalized leaching rate of the sample with 60 wt.% of dopant was about 2.5 × 10 −7 g m −2 d −1 on the 35th day. In this study, a free occupation of simulated waste ions in ceramics was proposed.
研究领域:
材料科学
·
核废物管理
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF ALLOYS AND COMPOUNDS
·
2025
·
IF 6.3
Zhenfeng Guo,Tianqi Zhang,Xiaoqing Wang,Chenyu Mi,Zitao Guo,Guanghui Zhang,Benxue Liu,Yongshuai Xie,Luyi Zhu,Xinqiang Wang
The demands for high-temperature resistant thermal insulation materials in the realms of aviation, aerospace, and military technology are constantly escalating. The development of thermal insulation materials capable of stable operation at high temperatures above 1200 °C has become a significant research direction. In response, Gd 2 Zr 2 O 7 has emerged as a promising flexible thermal insulation material due to its low thermal conductivity, high melting point and thermal stability. This study addresses the challenge of fabricating Gd 2 Zr 2 O 7 nanofibers with superior mechanical properties and high-temperature stability. Defect fluorite-structured Gd 2 Zr 2 O 7 nanofibers were prepared by using the sol-gel method and electrospinning technique. The resulting nanofibers exhibited small grain size (84.5 nm@1300 °C), dense structure and high tensile strength (1.69 MPa@1100 °C), excellent bending fatigue resistance (recoverable bending strain up to 80 %). Additionally, the nanofibers demonstrated high strength retention (68 %) and low area shrinkage (<2 %) after heat-treatment at 1300 °C, indicating excellent high-temperature stability. The thermal conductivity of Gd 2 Zr 2 O 7 nanofiber membranes was very low (26.2 mW·m −1 ·K −1 @1300 °C), showcasing outstanding high-temperature insulation property. Therefore, the simple and effective preparation method proposed in this study, along with the superior thermal insulation performance of the Gd 2 Zr 2 O 7 nanofibers, shows great potential for large-scale practical applications.
研究领域:
材料科学
·
热能工程
✓ 已验证
产品关联
DOI
高影响因子
CERAMICS INTERNATIONAL
·
2023
·
IF 5.2
Zhangyi Huang,Wanying Guo,Yang Shi,Ruichong Chen,Zhijun Wang,Yutong Zhang,Junjing Duan,Jianqi Qi,Haomin Wang
The Gd 2 Zr 2 O 7 (GZO)-based ceramic waste form exhibits promising potential for radioactive waste immobilization. However, the isomorphic immobilization capacity and irradiation effects of GZO-based ceramic waste forms with varying waste loads remain inadequately understood. This study employed a facile combustion method to synthesize ceramic powders and utilized conventional sintering with a relatively short dwelling time to fabricate GZO-based ceramic waste forms. We investigated the isomorphic immobilization behavior and He ion irradiation effects of the synthesized waste forms. The outcomes demonstrate that GZO effectively immobilizes simulated waste composed of 11 types of oxides, achieving a waste load as high as 50 wt% with a single pyrochlore phase and homogeneous element distribution. Under He + irradiation, aggravated structural degradations, including exacerbated lattice swelling, increased amorphization degree, and premature He bubble chain/microcrack formation, were observed in GZO-based waste forms with an increasing waste load.
研究领域:
材料科学
·
核能工程
·
放射化学
✓ 已验证
产品关联
DOI
高影响因子
CERAMICS INTERNATIONAL
·
2021
·
IF 4.527
Kui Liu,Kuibao Zhang,Ting Deng,Jianjun Zeng,Baozhu Luo,Haibin Zhang
Gd 2 Zr 2 O 7 ceramic is considered as one of the most promising host minerals for the immobilization of high-level radioactive wastes . Here, the effects of grain size on the aqueous durability of Gd 2 Zr 2 O 7 ceramics were studied. Two kinds of leaching experiments were used to research Gd 2 Zr 2 O 7 ceramic powders and bulks with different grain sizes (5 nm, 78 nm, 1 μm and 18 μm). The results demonstrate that the normalized leaching rates decrease with the increase of grain size. Through characterization and analysis, it is concluded that the hydrolysis reactions of Gd 2 Zr 2 O 7 occur in the leaching experiment and the hydrolysates are Gd(OH) 3 and Zr(OH) 4 . Besides, all the samples after leaching exhibit slight lattice contraction, which decreases with the increase of crystal grain size. The influence of leaching on the elemental distribution is most significant for the sample with grain size of 5 nm. This study has theoretical guiding significance for the application of Gd 2 Zr 2 O 7 immobilization.
研究领域:
材料科学
·
核废料管理
·
环境化学
✓ 已验证
DOI
高影响因子
JOURNAL OF NUCLEAR MATERIALS
·
2017
·
IF 2.048
Zhangyi Huang,Zhangkai Cao,Ke Shi,Jianqi Qi,Mao Zhou,Zhe Tang,Wei Han,Xinyue Diao,Jun Tang,Tiecheng Lu
For Gd 2 Zr 2 O 7 , nanograin ceramics with high relative densities (95%–97.4%) and small average grain sizes (61 nm - 82 nm) were successfully fabricated for the first time using field assisted sintering technique (FAST), also known as spark plasma sintering (SPS) method, in which nanopowders with an average crystallite size of 5.9 nm were synthesized via a non-aqueous gel-combustion method. Temperature was varied over a broad range to investigate its influence on the densification mechanism, microstructure evolution and hardness. The results revealed that both relative density and grain size increase with the increase of sintering temperature . The densification processes were divided to three stages. 1250 °C–1300 °C is the most suitable temperature range to fabricate dense Gd 2 Zr 2 O 7 nanograin ceramics with comparatively high hardness by FAST.
研究领域:
材料科学
·
无机非金属材料
·
陶瓷工程
·
纳米材料
·
固态化学
·
烧结工艺
✓ 已验证
DOI
高影响因子
CERAMICS INTERNATIONAL
·
2020
·
IF 3.83
Kui Liu,Kuibao Zhang,Ting Deng,Weiwei Li,Baozhu Luo,Haibin Zhang
Gd 2 Zr 2 O 7 ceramics demonstrate important prospect in the immobilization of high-level radioactive wastes (HLWs). In this study, Gd 2 Zr 2 O 7 nanoceramics were fabricated using two-step method, where Gd 2 Zr 2 O 7 nanopowder was firstly synthesized by solvothermal method and Gd 2 Zr 2 O 7 nanoceramics were subsequently sintered via self-propagating chemical furnace plus quick pressing (SCF/QP). The characterization results display that the Gd 2 Zr 2 O 7 nanocrystalline ceramics with average grain size of 78 nm and bulk density of 5.53 g cm −3 were successfully prepared. The results of MCC-1 static leaching experiments show that the normalized release rate (LR i ) of Gd is 2.2 × 10 −2 g m −2 •d −1 on the first day and converges to 1.2 × 10 −3 g m −2 •d −1 after 42 days. Zr shows superior chemical stability as the 21 days LR Zr value is as low as 2.7 × 10 −6 g m −2 •d −1 , which becomes constant as the leaching duration prolongs.
研究领域:
材料科学
·
核能工程
·
环境科学
✓ 已验证
DOI
高影响因子
JOURNAL OF ALLOYS AND COMPOUNDS
·
2023
·
IF 6.2
Qi Wu,Mengmeng Fu,Chenzhang Gu,Yinzhen Wang,Lu Yao,Cailin Wang
Red phosphors with good thermal stability, high color temperature and color purity are critical in high power warm white LED devices. Herein, a series of single and co-doped Tb 3+ ,Eu 3+ polychromatic phosphors with pyrochlore structure based on Gd 2 Zr 2 O 7 have been prepared for the first time by a conventional solid phase reaction method. Compared to single doped Eu 3+ phosphors, Tb 3+ ,Eu 3+ co-doped phosphors possess following advantages: improved UV absorption, increased photoluminescence intensity, extended luminescence range and improved thermal stability. At room temperature, the Gd 2 Zr 2 O 7 :Tb 3+ ,Eu 3+ phosphors exhibited a gradual shift from yellow-green emission at 544 nm to orange-red emission at 613 nm with increasing doping of Eu 3+ ions. Energy transfer efficiency has been evaluated to be 71% by analyzing the fluorescence lifetime of Tb 3+ ions. The concentration quenching mechanism under different conditions was analyzed in detail and it was concluded that the quenching of Tb 3+ is caused by dipole-dipole interaction. In addition, the activation energy (ΔE a ) of the Gd 1.92 Zr 2 O 7 :0.03Tb 3+ ,0.05Eu 3+ phosphor was calculated to be as high as 0.2674 eV compared to other Tb 3+ , Eu 3+ co-doped phosphors, demonstrating its high thermal stability. WLEDs devices based on Gd 1.92 Zr 2 O 7 :0.03Tb 3+ ,0.05Eu 3+ phosphors have been prepared, which have low correlated color temperature (CCT) (5283 K), high color rendering index Ra = 85.5 K) and CIE coordinates chromaticity coordinate (0.3371,0.3333). All of the results show that Gd 2 Zr 2 O 7 :Tb 3+ ,Eu 3+ phosphors provide a new avenue to develop high quality red emission and high thermal stability phosphors for WLEDs.
研究领域:
材料科学
·
光电
·
光子学
·
固体物理
✓ 已验证
产品关联
DOI
高影响因子
RSC Advances
·
2017
·Vol. 7
·期 87
·54980-54985
·
IF 3.108
Zhe Tang,Zhangyi Huang,Jianqi Qi,Xiaofeng Guo,Wei Han,Mao Zhou,Shuting Peng,Tiecheng Lu
Defect-fluorite structured Gd2Zr2O7 nanoparticles were successfully synthesized via a homogeneous precipitation-solvothermal method using urea as a precipitant. The obtained nanoparticles were characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM), Brunauer–Emmett–Teller (BET) analysis and transmission electron microscopy (TEM). Compared to the traditional solvothermal method, this homogeneous precipitation-solvothermal method has the advantage of producing nanoparticles with small grain sizes, a narrow size-distribution, high surface areas and little agglomeration. Particularly, the mean crystallite size of Gd2Zr2O7 obtained by this method is 20–30 nm, providing a great opportunity of using these nanoparticles as starting nano-sized building blocks for low temperature preparation of homogeneous and dense ceramics.
研究领域:
材料科学
·
纳米技术
·
陶瓷
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF ALLOYS AND COMPOUNDS
·
2024
·
IF 5.8
Yurong Song,Gang Qu,Xi Li,Dandan Huang
Sm 2 Zr 2 O 7 and Gd 2 Zr 2 O 7 are two promising transparent ceramic materials with high density and effective atomic number. However, the phase diagram of Gd 2 O 3 -Sm 2 O 3 -ZrO 2 system has not been systematically studied. To determine the phase relationship of the ternary system Gd 2 O 3 -Sm 2 O 3 -ZrO 2 at 1600°C and 1400°C, a serious of ceramic samples were prepared and studied by X-ray diffraction, scanning electron microscope , and electron probe microanalysis . In the range of 66.6 mol.% ZrO 2 , the solubility of Gd 2 O 3 is 20–22.5 mol.% at 1600°C, and the binary intermediate phases Sm 2 Zr 2 O 7 and Gd 2 Zr 2 O 7 form a continuous solid solution at 1400°C. Using the experimental data as a foundation, thermodynamic modeling was performed using the approach. Based on the experimental data, the mixing parameters of fluorite , B and C phases were optimized, and thermodynamic modeling was performed using the CALPHAD (CALculation of PHAse Diagram) method. For the first time, a self-consistent database for Gd 2 O 3 -Sm 2 O 3 -ZrO 2 ternary system was established.
研究领域:
材料科学
·
无机化学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF THE EUROPEAN CERAMIC SOCIETY
·
2016
·
IF 2.933
Mao Zhou,Zhangyi Huang,Jianqi Qi,Nian Wei,Di Wu,Qinghua Zhang,Shanshan Wang,Zhao Feng,Tiecheng Lu
Gd 2 Zr 2 O 7 nanoceramics were fabricated using pressureless sintering method, in which the nanopowders were synthesized via solvothermal approach. The effects of starting powders on grain growth and densification during sintering of ceramics were revealed. Two distinct pressureless sintering methods were investigated, including conventional and two-step sintering. The sample grain size increases abruptly as sintering temperature increases during conventional sintering. In contrast, in two-step sintering, abnormal or discontinuous grain growth was suppressed in the second step, leading to Gd 2 Zr 2 O 7 nanoceramics formation (average grain size 83 nm, relative density ∼93%). Such distinct behaviors may originate from the interplay between kinetic factors such as grain boundary migration and diffusion. Moreover, suppression of grain growth and promotion of densification in the two-step sintering are mainly due to dominant role of grain boundary diffusion during the second-step sintering process.
研究领域:
材料科学
·
陶瓷
·
纳米材料
·
烧结技术
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）