JOURNAL OF MATERIALS SCIENCE-MATERIALS IN ELECTRONICS
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2014
·Vol. 26
·期 1
·369-376
·
IF 1.966
Wang Hongguang,Xiong Xinqian,Xu Jinbao,Wang Lei,Bian Liang,Ren Wei,Chang Aimin
Preferred (100)-oriented and complete (100)-oriented LaMn 0.6 Al 0.4 O 3 thin films were deposited on (100)-LaNiO 3 -coated silicon substrates by spin-coating method. Complex impedance spectroscopy was used to provide a convincing evidence for the existence of grain and grain boundary that were separated in the frequency domain in impedance spectrum. It suggests that the better grain orientation is effective in lowering the resistivity and activation energy but with little influenced on grain boundary. The analysis of impedance dependent on frequency, reveals that the relaxation is a thermally activation process. The grain and grain boundary conduction obey the Arrhenius behavior with activation energy 1.2294–1.3273 eV. The mechanism associated with the change of the electrical properties of the thin films is discussed.
研究领域:
材料科学
·
固体物理
✓ 已验证
DOI
高影响因子
HIGH PERFORMANCE POLYMERS
·
2018
·
IF 1.047
Yanhua Yang,Pan Jin,Jinzhang Liu,Shijin Ding,Lin Chen,Yueying Chu,Yingzhong Shen
The polyimide (TPA-Cz PI) was synthesized by the reaction of 9-(4′-(4′-diphenylamino)phenylbenzyl)-3,6-diaminocarbazole with 2,2′,3,3′-biphenyltetracarboxylic dianhydride through a classical two-step polymerization process. It exhibited excellent organo-solubility and self-extinguishing property. The synthesized TPA-Cz PI shown excellent film formation. The TPA-Cz PI film sandwiched between an indium tin oxide bottom electrode and Al top electrode. And the fabricated memory device exhibited ternary rewritable storage property in the bias with good data retention and the current ratio of 104:102:1 for ON2, ON1, and OFF states. Its current conduction mechanism by the I-V curves of different conduction models based on the experimental data was analyzed and used to illuminate the physical nature of resistance switching effects. The experimental result indicates that field-induced conformational ordering of the TPA-Cz PI chains and charge-transfer interaction between electron-donor and electron-withdrawing are responsible for the switching behavior. This work can provide a sketch for the design and selection of ternary state resistance random access memory materials in future research.
研究领域:
材料科学
·
电子工程
✓ 已验证
DOI
高影响因子
CERAMICS INTERNATIONAL
·
2024
·
IF 5.1
Meng-Han Yan,Zhi-Fei Zhang,Hai-Hua Huang,Zi-Liang Li,Peng Li,Ji-Gong Hao,Wei Li,Juan Du,Mahesh Kumar Joshi,Peng Fu
In this work, a series of x Sm 2 O 3 -(1- x ) CaCu 3 Ti 4 O 12 ( x Sm 2 O 3 -(1- x )CCTO, x = 0.00–0.05) negative temperature coefficient (NTC) ceramics were prepared by a solid-state method. The influence of Sm 2 O 3 content on electrical properties was examined using microstructural, band gap, morphological, Direct Current (DC) resistivity, and impedance spectroscopy analysis. The increase in Sm 2 O 3 content resulted in a gradual decrease of the resistivities ( ρ 25 ), thermal constants ( B 25/75 ), activation energies for electrical conduction ( E a ) and activation energies of the relaxation process ( E relax ) from 1.16 × 10 7 Ω cm, 6387 K, 0.5456 eV and 0.5592 eV to 3.43 × 10 5 Ω cm, 4149 K, 0.4088 eV and 0.4115 eV respectively. First-principles calculations revealed a reduction in the band gap by adding Sm 2 O 3 , partially explaining the decrease in electrical resistivity. In-situ XPS analysis elucidated a relationship between conduction mechanism of Sm 2 O 3 -doped CCTO ceramics and electron hopping. Impedance analyses showed that both grains and grain boundaries contributed to the NTC effect of ceramics. The electrical inhomogeneity arose from grains and grain boundaries, while local relaxation was due to the short-range motion of charge carriers.
研究领域:
材料科学
·
物理学
✓ 已验证
DOI
高影响因子
CRYSTENGCOMM
·
2022
·Vol. 24
·期 18
·3469-3474
·
IF 3.756
Huiqi Wang,Jiacheng Han,Mei Wang,Liyong Wang,Suping Jia,Honghong Cao,Shengliang Hu,Yan-Bing He
Crystalline boron quantum dots (BQDs) are, for the first time, synthesized through a typical bottom-up approach by using ammonium pentaborane and boric acid as precursors under hydrothermal synthesis conditions. The results show that the as-prepared BQDs are evenly distributed with a narrow size of ca. 6.4 nm, good dispersibility and high stability in aqueous solution. As a novel application, a mixture of the as-prepared BQDs and polyvinyl pyrrolidone (PVP) is used as an active layer for the fabrication of a BQD–PVP memory device, which exhibits typical bistable electrical switching behavior and a nonvolatile rewritable memory effect with a high ON/OFF current ratio of more than 103 and good stability at a read voltage of 0.1 V. The ON/OFF current ratio of this device is high enough to ensure a low misreading rate through the precise control of the ON and OFF states, making the mixture of BQD–PVP have great potential in flash memory devices. The conduction mechanism of the BQD–PVP memory device is disclosed using the space-charge-limit current model. The charge injection/extraction behavior of the BQD–PVP active layer is investigated to clarify the electronic transition. The charge carriers were first injected into the PVP layer through a thermionic process, blocking the injection to the BQDs due to the large injection barrier between PVP and the BQDs. The charge carriers transferred between PVP and the BQDs and were finally trapped by the BQDs at a higher voltage. This work is desirable for low-voltage and overlong read cycle memory devices.
研究领域:
材料科学
·
纳米技术
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电子器件
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应用物理学
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高分子化学
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）