This paper studied the low-resistance ohmic contacts on InAlN/GaN with metal–organic chemical vapor deposition(MOCVD)regrowth technique.The 150-nm regrown n-InGaN exhibits a low sheet resistance of 31Ω/□,resulting ...This paper studied the low-resistance ohmic contacts on InAlN/GaN with metal–organic chemical vapor deposition(MOCVD)regrowth technique.The 150-nm regrown n-InGaN exhibits a low sheet resistance of 31Ω/□,resulting in an extremely low contact resistance of 0.102Ω·mm between n^(+)-InGaN and InAlN/GaN channels.Mask-free regrowth process was also used to significantly improve the sheet resistance of InAlN/GaN with MOCVD regrown ohmic contacts.Then,the diffusion mechanism between n^(+)-InGaN and InAlN during regrowth process was investigated with electrical and structural characterizations,which could benefit the further process optimization.展开更多
Asynergistic inhibition study was carried out on an aluminium/copper galvanic coupling model in neutral aerated NaCl solution using scanning vibrating electrode technique(SVET).The approach allows the simulation of th...Asynergistic inhibition study was carried out on an aluminium/copper galvanic coupling model in neutral aerated NaCl solution using scanning vibrating electrode technique(SVET).The approach allows the simulation of the local micro-galvanic cells of AA2024-T3 obtained from the potential difference between the intermetallic particles(IMPs)and the aluminium matrix.The inhibition effect of CeCl3 and 3-Amino-1,2,4-triazole-5-thiol(ATAT)was demonstrated by the reduction in the galvanic current density over Al and Cu surfaces.An improved inhibition from positive synergistic effect was revealed by the combination of the two inhibitors after 24 h of immersion,with the best inhibition recorded for Ce1.5ATAT3.5.Scanning electron microscopy(SEM),X-ray photoelectron spectroscopy(XPS)and time of flight secondary ion mass spectrometry(ToF-SIMS)were used to characterize the Ce-and ATAT-based complex film formed and to illustrate the mechanism of inhibition.展开更多
Determining the distribution of alloying elements,particularly lithium,is crucial for a holistic understanding of magnesium-lithium-based alloys.In this work,a bespoke ratio spectrum-imaging method based on electron e...Determining the distribution of alloying elements,particularly lithium,is crucial for a holistic understanding of magnesium-lithium-based alloys.In this work,a bespoke ratio spectrum-imaging method based on electron energy-loss spectroscopy,in combination with time-of-flight secondary ion mass spectrometry,energy-dispersive X-ray spectroscopy and Z-contrast imaging,was applied to an as-rolled LAZ941 alloy(Mg-9Li-4Al-1Zn in wt.%).This was done to characterize the distribution of alloying elements,including the distribution of solute in the magnesium matrix.The applications of different mapping techniques revealed that precipitates with two different morphologies are rich in Li,Al and Zn,compared to their surrounding matrix.Additionally,it was confirmed that theβ-phase of the alloy contains higher Li and lower Mg concentrations when compared to theα-phase.This study demonstrated the effectiveness and accuracy of the ratio spectrum-imaging method for mapping the elemental distribution(including lithium)in a range of Li-containing materials.展开更多
基金the Fundamental Research Funds for the National Key Research and Development Project of China(Grant No.2020YFB1807403)the National Natural Science Foundation of China(Grant Nos.62174125 and 62131014)+1 种基金the Fundamental Research Funds for the Central Universities(Grant Nos.QTZX22022 and YJS2213)the Innovation Fund of Xidian University.
文摘This paper studied the low-resistance ohmic contacts on InAlN/GaN with metal–organic chemical vapor deposition(MOCVD)regrowth technique.The 150-nm regrown n-InGaN exhibits a low sheet resistance of 31Ω/□,resulting in an extremely low contact resistance of 0.102Ω·mm between n^(+)-InGaN and InAlN/GaN channels.Mask-free regrowth process was also used to significantly improve the sheet resistance of InAlN/GaN with MOCVD regrown ohmic contacts.Then,the diffusion mechanism between n^(+)-InGaN and InAlN during regrowth process was investigated with electrical and structural characterizations,which could benefit the further process optimization.
基金This work was financially supported by the National Natural Science Foundation of China(Nos.51571202 and 51001109).
文摘Asynergistic inhibition study was carried out on an aluminium/copper galvanic coupling model in neutral aerated NaCl solution using scanning vibrating electrode technique(SVET).The approach allows the simulation of the local micro-galvanic cells of AA2024-T3 obtained from the potential difference between the intermetallic particles(IMPs)and the aluminium matrix.The inhibition effect of CeCl3 and 3-Amino-1,2,4-triazole-5-thiol(ATAT)was demonstrated by the reduction in the galvanic current density over Al and Cu surfaces.An improved inhibition from positive synergistic effect was revealed by the combination of the two inhibitors after 24 h of immersion,with the best inhibition recorded for Ce1.5ATAT3.5.Scanning electron microscopy(SEM),X-ray photoelectron spectroscopy(XPS)and time of flight secondary ion mass spectrometry(ToF-SIMS)were used to characterize the Ce-and ATAT-based complex film formed and to illustrate the mechanism of inhibition.
基金Australian Research Council(ARC)for the financial support of this work(Grant No.DP190103592)funded by ARC grants LE110100223(FEI F20),LE0454166(FEI Titan3),LE170100118(Thermo Scientific Spectra-φ),and LE200100132(Thermo Scientific Helios)。
文摘Determining the distribution of alloying elements,particularly lithium,is crucial for a holistic understanding of magnesium-lithium-based alloys.In this work,a bespoke ratio spectrum-imaging method based on electron energy-loss spectroscopy,in combination with time-of-flight secondary ion mass spectrometry,energy-dispersive X-ray spectroscopy and Z-contrast imaging,was applied to an as-rolled LAZ941 alloy(Mg-9Li-4Al-1Zn in wt.%).This was done to characterize the distribution of alloying elements,including the distribution of solute in the magnesium matrix.The applications of different mapping techniques revealed that precipitates with two different morphologies are rich in Li,Al and Zn,compared to their surrounding matrix.Additionally,it was confirmed that theβ-phase of the alloy contains higher Li and lower Mg concentrations when compared to theα-phase.This study demonstrated the effectiveness and accuracy of the ratio spectrum-imaging method for mapping the elemental distribution(including lithium)in a range of Li-containing materials.
