CERAMICS INTERNATIONAL
·
2022
·Vol. 49
·期 2
·1846-1854
·
IF 5.532
Xinkun Liu,Ying Dai,Xinmei Pei,Wen Chen
The electrocaloric (EC) effect cooling technique of environmentally friendly lead-free thin film materials driven by electric fields has recently gained tremendous attention due to the urgent demand for microelectronic and integrated circuit refrigeration devices. However, the widespread use of lead-free materials in EC devices is seriously hindered due to the small electrocaloric temperature change (ΔT) within a narrow operation temperature span (T span ) near room temperature. Here, lead-free Ba 0.85 Ca 0.15 Zr 0.1 Ti 0.9-x Sn x O 3 (BCZT-xSn, 0 ≤ x ≤ 0.03) thin films were prepared on substrates (Pt/Ti/SiO 2 /Si) via a sol-gel route. The BCZT-0.02Sn thin film presents an excellent EC effect (ΔT = 32.74 K, ΔS = 37.18 J kg −1 K −1 ) and large EC strength (ΔT/ΔE = 0.033 K cm kV −1 , ΔS/ΔE = 0.037 J cm K −1 kg −1 kV −1 ) over a wide T span (∼26 K) under 1000 kV cm −1 near room temperature. The giant ΔT is mainly attributed to the emergence of an intermediate O phase and the formation of a multiphase (R, O and T phases) coexistence structure at room temperature, while the diffuse phase transition behavior is responsible for the wide T span . Our study provides a new idea for developing environment-friendly EC materials with an excellent room-temperature ΔT over a broad operational temperature region.
研究领域:
材料科学
·
功能材料
·
固态物理
·
环境友好材料
·
制冷技术
✓ 已验证
DOI
高影响因子
RSC Advances
·
2019
·Vol. 9
·期 14
·8039-8047
·
IF 3.049
Peng Gu,Xinghua Zhu,Dingyu Yang
Mn-doped ZnO (MZO) films were prepared on glass substrates using sol–gel dip-coating technology. The microstructural, morphological, optical and photoelectric properties of MZO films were investigated at different withdrawal speeds (WS: 20, 40, 60 and 80 mm s−1). The X-ray diffraction (XRD) patterns showed that all the films obtained were polycrystalline with a hexagonal structure, and the highest crystallinity of MZO films was observed as films were deposited at 40 mm s−1. The UV-Vis spectra revealed that the average optical transmittance of all samples was over 60% and the energy band gap of films decreased from 3.616 to 3.254 eV with the increase in withdrawal speed. The formed Au/MZO/Au photodetectors (PDs) indicate that a device prepared at 40 mm s−1 shows superior properties both in response speed and detection capability, and the rise time is 1.871 s and fall time is 3.309 s at 365 nm for 3 V bias and the detectivity (D*) reaches ∼1.7 × 1010 Jones. Moreover, the responsivity of PDs is also affected by the distance between Au electrodes and external bias. This research provides a simple way to fabricate the UV PDs based on MZO films with faster response and higher detectivity.
研究领域:
材料科学
·
半导体物理
·
光电子学
·
薄膜技术
·
纳米材料
✓ 已验证
DOI
高影响因子
JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS
·
2024
·
IF 2.5
Jitao Zhang,Xingkui Mu,Qingfang Zhang,Natallia Poddubnaya,Dmitry Filippov,Jiagui Tao,Fang Wang,Liying Jiang,Lingzhi Cao
Development of high-quality ferrites behaved enhanced properties via inclusion of ions in 3d n and 4f n series are desirable for efficient power conversion solid-state devices. Nevertheless, inadequate microscopic behaviors with complex chemistry in materials enables researchers to design and produce the macroscopic target device that remained rudimentary and mindless. In this work, the microscopic properties in nickel-zinc spinel ferrite series of Ni 0.8 Zn 0.2 Sm x Fe 2- x O 4 ( x = 0, 0.02, 0.04, 0.06, 0.08) encompassing XRD, SEM, EDS, VSM, FTIR and ESR were systemically characterized, and the evolutionary mechanism of the corresponding structural, micro-structure, elemental composition and distribution, magnetic, cations exchange, and micro-magnetic behavior was profoundly revealed. Under microscopic examinations, the optimum composition at x = 0.02 with well-arranged spinel structure, dense texture with expected elemental composition, favorable soft magnetic properties and micro-magnetic behaviors is evident. Fortunately, this optimum is in coincidence with the achievable maximum magneto-mechanical coefficient, even the macroscopic electric properties with stronger magnetoelectric (ME) interactions and higher power conversion efficiency (PE) in tri-layered ME samples as expected. Experimental results show that the eventual PE reaches its maximum of 75.67 % under R opt = 33kΩ for samples at x = 0.02, and exhibit a 2.24 times higher PE than that of sample without samarium substitution. These findings provide a holographic perspective to connect the microscopic beneficial effects of materials to bulk device that are promising for efficient power conversion solid-state electronics.
研究领域:
材料科学
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磁性材料
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固态电子学
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功能陶瓷
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能源转换技术
✓ 已验证
DOI
高影响因子
RSC Advances
·
2015
·Vol. 5
·期 93
·76116-76121
·
IF 3.84
Hailing Xu,Huang Jiang,Xingwei Li,Gengchao Wang
Polyaniline doped with lignosulfonate (PANI/LGS) was prepared by using a facile oxidative polymerization of aniline with (NH4)2S2O8 as an oxidant, and the structure and morphology of PANI/LGS were investigated. As an active material for supercapacitors, the capacity retention rate of PANI/LGS was 75.1% with a growth of current density from 0.2 to 10 A g−1, indicating a high rate performance, and that of PANI was only 38.3%. For PANI/LGS, a specific capacitance of 377.2 F g−1 remained at 10 A g−1, and that of PANI was 183.7 F g−1. Moreover, the cycling stability was also measured in a two-electrode symmetrical capacitor at a current density of 1.0 A g−1. The capacity retention rate of PANI/LGS was 74.3% after 10 000 cycles, and that of PANI was 52.8%.
研究领域:
材料科学
·
电化学
·
高分子化学
·
能源存储
·
纳米材料
✓ 已验证
DOI
高影响因子
JOURNAL OF MATERIALS SCIENCE-MATERIALS IN ELECTRONICS
·
2020
·Vol. 31
·期 11
·8403-8412
·
IF 2.22
Wang Ting,Ma Qing,Gao Shang,Huang Mengshi
Highly regular TiO 2 nanotube arrays (TNTs) with interstitial nitrogen as the dominant point defect have been successfully prepared by annealing the as-anodized TNTs in N 2 in a temperature range of 400–650 °C. Using analysis methods that include field emission scanning electron microscopy, X-ray diffraction patterns, and Raman spectroscopy, the thermal stability of TNTs annealed in N 2 was found to be higher than that of TNTs annealed in O 2 . The interstitial nitrogen is considered as the dominant point defect in TNTs annealed in N 2 , which results in the notably improved thermal stability of the highly ordered TNTs. However, the content of hydroxyl oxygen on the surface of TNTs is significantly influenced by annealing temperature, which is closely related to photocatalytic activity. Optimized photocatalytic property of photodegradation of MO with a pseudo-first-order reaction constant k value of (5.065 ± 0.139) × 10 –2 h −1 is achieved for TNTs annealed in N 2 at 600 °C. These findings serve to provide simple and versatile guidelines to fabricate highly ordered TNTs with controllable point defects, enhanced thermal stability, and a high level of photocatalytic activity.
研究领域:
材料科学
·
纳米科技
·
光催化
·
表面化学
·
功能材料
✓ 已验证
DOI
高影响因子
APPLIED PHYSICS A-MATERIALS SCIENCE & PROCESSING
·
2020
·Vol. 126
·期 9
·711
·
IF 1.81
Liu Dong,Jin Yahong,Xiong Guangting,Lv Yang,Wu Haoyi,Ju Guifang,Chen Li,Hu Zhengfa,Hu Yihua
A series of broadband blue-green phosphors Rb 0.5+ y Na 1.5− y (Li 3 SiO 4 ) 2 : x Eu 2+ (0 ≤ y ≤ 0.4, 0.01 ≤ x ≤ 0.08) were synthesized by the high-temperature solid-state reaction. The powder X-ray diffraction was employed to explore the crystal structural evolution from RbNa 3 (Li 3 SiO 4 ) 4 to RbNa(Li 3 SiO 4 ) 2 with the increasing of Rb + . The spectra show the optimized composition was determined as y = 0.4. The luminescence, lifetime decay curves and thermal steadily spectra of Rb 0.9 Na 1.1 (Li 3 SiO 4 ) 2 : x Eu 2+ phosphors were investigated in detail. The phosphor of Rb 0.9 Na 1.1 (Li 3 SiO 4 ) 2 :Eu 2+ shows suitable visible spectra (450–550 nm, cover the blue and green regions), excellent thermal quenching (104%@150 °C of the initial integrated intensity at room temperature under 396 nm excitation) and broad excitation spectrum (320–450 nm). Finally, a commercial near-UV LED devices (395 nm) were fabricated with the Rb 0.9 Na 1.1 (Li 3 SiO 4 ) 2 :Eu 2+ phosphor as blue-green and commercial red phosphor CaAlSiN 3 :Eu 2+ with a warm color temperature of 3104 K and a color rendering index of 91.8. This result indicated that Rb 0.9 Na 1.1 (Li 3 SiO 4 ) 2 :Eu 2+ may be a promising blue-green phosphor for indoor lighting.
研究领域:
材料科学
·
发光材料
·
固体化学
·
照明技术
·
无机化学
✓ 已验证
DOI
高影响因子
SCRIPTA MATERIALIA
·
2019
·
IF 4.539
Qingshuang Ma,Feng Lan,Xinhua Li,Zunfeng Du,Huijun Li,Zongqing Ma
In this work, the superconducting properties of FeSe 1−x S x with 0 ≤ x ≤ 0.5 were studied. With S doping, T c is enhanced and shows a dome shape in the studied composition range. XRD measurements demonstrate that S substituting Se sites introduces positive chemical pressure, which can suppress the orbital ordering, manifesting as the decrease of T s . Hall measurements demonstrate that S doping can effectively tune the charge carriers and make hole-type carriers predominant. However, no maxing T c is obtained as T s vanishes in FeSe 0.7 S 0.3 , indicating the nematic order has no universal influence on the superconductivity of FeSe system.
研究领域:
凝聚态物理
·
材料科学
·
低温物理学
·
强关联电子系统
✓ 已验证
DOI
高影响因子
JOURNAL OF MEMBRANE SCIENCE
·
2018
·
IF 6.578
Xiaoxiao Zhang,Qingting Liu,Lei Xia,Dongyang Huang,Xudong Fu,Rong Zhang,Shengfei Hu,Feng Zhao,Xiao Li,Xujin Bao
To broaden the operating temperature range of phosphoric acid (PA) doped polybenzimidazole membrane-based proton exchange membrane fuel cells (PEMFCs) toward low temperatures, a novel series of poly(2,5-benzimidazole) (ABPBI)/sulfonated sepiolite (S-Sep) composite membranes (ABPBI/S-Sep) with low PA doping levels (DLs) were prepared via in-situ synthesis. The desirably enhanced mechanical, thermal, and oxidative stabilities of ABPBI/S-Sep composite membranes were achieved by constructing ABPBI chains arranged along the sepiolite (Sep) fibers and acid-base crosslinks formed between S-Sep fibrous particles and ABPBI chains. Benefiting from the richness of high temperature stable bound water and the excellent water absorbability of Sep particles that enable the formation of additive proton conducting paths, the composite membranes retained bounded PA and achieved much higher proton conductivities under both anhydrous and hydrous conditions compared to PA-doped ABPBI membranes. Proton conductivity values above 0.01 S/cm at 40–90 °C/20–98% RH conditions and 90–180 °C/anhydrous conditions as well as peak power density of 0.13 and 0.23 W/cm 2 at 80 and 180 °C with 0% RH, respectively from the ABPBI/2S-Sep composite membrane are more holistic compared to Nafion at low temperatures and polybenzimidazole-based membranes at high temperatures, respectively. The excellent properties of ABPBI/S-Sep composite membranes suggest them as prospective candidates for PEMFCs applications in a wide temperature range.
研究领域:
材料科学
·
能源科学
✓ 已验证
产品关联
DOI
高影响因子
ELECTROCHIMICA ACTA
·
2019
·
IF 5.383
Tan Dang,Lei Wang,Donghai Wei,Guiqing Zhang,Qinggang Li,Xiaojia Zhang,Zuoying Cao,Guanhua Zhang,Huigao Duan
Low-cost and resourceful transition metal phosphides (TMPs), as a new kind of pseudocapacitive materials, have received considerable interest for electrochemical energy storage/conversion. Combination of TMPs and carbon nanostructures is supposed to greatly improve the charge storage capability due to the synergistic effect. In this work, nickel cobalt phosphides nanosheets supported by P doped C spheres (P-CSs@Ni-Co-P NSs) composites with different Ni/Co molar ratios (1:0, 1:1, 1:2, 1:4 and 0:1) were prepared by in-situ bifunctional phosphorization of the as-synthesized CSs@Ni-Co-OH NSs precursor. The optimized 3D networked mesoporous P-CSs@Ni 1 -Co 2 -P NSs electrode exhibits a remarkable specific capacitance of 1040.3 F g −1 at 1 A g −1 and excellent rate capability with a capacitance retention of 49.2% even at 30 A g −1 , which are much higher than those of A-CSs@Ni 1 -Co 2 -O NSs (870.5 F g −1 at 1 A g −1 , 37.4% at 30 A g −1 ) and Ni 1 -Co 2 -P NSs (500.5 F g −1 at 1 A g −1 , 40.0% at 30 A g −1 ). The improved supercapacitive performances are attributed to the 3D mesoporous nanosheets network and bifunctional phosphorization treatment which lead to enhancement of conductivity. Meanwhile, Ni-Co bimetallic phosphide with abundant oxidation states facilitates redox charge transfer efficiently. Furthermore, P-CSs@Ni 1 -Co 2 -P NSs assembled asymmetric supercapacitors (ASC) achieve outstanding cycling stability with no decay of capacitance after 20000 cycles. Additionally, the charge storage kinetic of the device is further investigated, indicating that fast surface-control capacitive behavior is dominant at high current densities.
研究领域:
材料科学
·
电化学
✓ 已验证
产品关联
DOI
高影响因子
DYES AND PIGMENTS
·
2023
·
IF 4.5
Fuhua Gao,Wasim Ullah Khan,Zhiyuan Cheng,Waheed Ullah Khan,Iqtidar Ahmad,Zhiqi Ye,Shenghong Yang,Yueli Zhang
Broadband near-infrared (NIR)-emitting materials have critical applications in biology, medical detection, and NIR night-vision. However, developing NIR phosphors with promising optical properties and excellent thermal stability is a great challenge for research. In this work, a novel NIR phosphor Cr 3+ and Yb 3+ doped CaSc 2 O 4 (CSO) is an evolving NIR emitting phosphor with decent optical properties , boosted emission intensity, and thermal stability that makes it a promising candidate with potential applications in NIR-LED and infrared night-vision. The implications of the fundamental electronic structure of CSO, including valence-band (VB) and conduction-band (CB) orbital character, are investigated. Under blue light excitation, CSO:Cr 3+ is settled with pure broadband NIR emissions (max = 920 nm, FWHM (full width at half maximum) = ∼310 nm) and good thermal stability . The occupation of two selectable lattice sites of Cr 3+ in CSO is discussed in detail. Furthermore, emission enhancements of samples are done by Cr 3+ and Yb 3+ codoping, effectively broadening FWHM to 351 nm and reducing thermal quenching. The energy transfer (ET) routes in CSO:Cr 3+ ,Yb 3+ are investigated based on PL lifetime and comprehensive kinetic ET model, revealing that the PL enhancements by Cr 3+ and Yb 3+ codoping mainly originate from the ET from Cr 3+ to Yb 3+ emitters with more efficient and thermally stable. Finally, an InGaN-LED device encapsulated using CSO:0.01Cr 3+ and CSO:0.01Cr 3+ ,0.01 Yb 3+ phosphor was fabricated. The fabricated NIR pc-LEDs are excellent candidates for NIR light sources in biological imaging and NIR night vision.
研究领域:
光学材料
·
生物医学成像
·
光电子学
·
无机发光材料
·
红外技术
·
固态照明
·
纳米生物技术
✓ 已验证
DOI
高影响因子
JOURNAL OF LUMINESCENCE
·
2021
·
IF 3.599
Yanting Zhu,Chenxia Li,Degang Deng,Hua Yu,Hao Li,Le Wang,Changyu Shen,Xufeng Jing,Shiqing Xu
A series of Eu 2+ /Cr 3+ co-doped BaAl 12 O 19 phosphor was synthesized by traditional high temperature solid stated method, and the temperature-sensitive characteristic of the phosphor was researched. Due to the temperature sensitivity of the fluorescence lifetime of Cr 3+ , the thermometry based on fluorescence lifetime can be realized. Furthermore, the emissions of Eu 2+ ion and Cr 3+ ion can be well separated, which shows the excellent signal recognition ability of this phosphor. The Eu 2+ /Cr 3+ co-doped BaAl 12 O 19 phosphor can be used for the thermometry based on fluorescence intensity ratio. A dual-mode optical thermometry is proposed and researched in the temperature range of 293–563 K by using the decay lifetime of Cr 3+ emission and in the temperature range of 295–476 K by using the fluorescence intensity ratio of Eu 2+ to Cr 3+ as temperature readout. The maximum values of relative sensitivity are 0.466% K −1 at 363 K and 0.259% K −1 at 476 K. The Eu 2+ /Cr 3+ co-doped BaAl 12 O 19 phosphor has excellent optical temperature characteristic , and its dual-mode thermometry characteristics provide convenience for the application of this material. This phosphor has potential application prospects in the field of optical thermometry.
研究领域:
材料科学
·
光学工程
·
无机化学
·
传感器技术
·
功能材料
✓ 已验证
DOI
高影响因子
CERAMICS INTERNATIONAL
·
2015
·Vol. 41
·期 4
·5498-5504
·
IF 2.605
Shizhou Pu,He Zheng,Zhenlian Chen,Meiya Li,Zhongqiang Hu,Jianbo Wang,Huamin Zou
The microstructures of Bi 0.85 Nd 0.15 FeO 3 ceramics were investigated by using transmission electron microscopy (TEM), high-resolution transmission electron microscopy (HRTEM), selected area electron diffraction (SAED), convergent-beam electron diffraction (CBED) and X-ray energy dispersive spectrometry (EDS). The superstructure phase related to 1/4( hh 0) p and 1/4(00 l ) p diffraction spots were observed in the samples. It is found that the superstructure phase can co-exist with R 3 c phase in a single grain. The bright and dark field images accompanied with SAED patterns provided evidences of the superstructure phase dispersed into the matrix with R3c symmetry and evolution of the domain. The ferroelectric domain wall was observed according to the displacement of Fe 3+ ions respect to Bi 3+ sub-lattice in the ferroelectric R 3 c phase based on HRTEM observations. The space group Pnam of the superstructure was identified by combining SAED and CBED techniques . EDS measurement revealed that the concentration of Nd in the Pnam phase is higher than that in R 3 c phase. This might mean that the transition from R 3 c to Pnam structure is due to the inhomogeneous distribution of the Nd concentration and the weakened stereochemical activity of Bi 3+ lone electron pair, arisen from the increase in Nd content.
研究领域:
材料科学
·
凝聚态物理
·
功能陶瓷
·
电子显微学
·
铁电材料
·
多铁材料
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）