In this study,the texture of a rolled Mg alloy is effectively modified through the application of precompression and subsequent annealing treatment,leading to a remarkable improvement in the bending formability of the...In this study,the texture of a rolled Mg alloy is effectively modified through the application of precompression and subsequent annealing treatment,leading to a remarkable improvement in the bending formability of the alloy at room temperature.Precompression induces lattice reorientation through{10-12}twinning,and annealing treatment reduces the stored strain energy of the precompressed material,which results in the formation of a stable grain structure with two dominant texture components.With an increase in precompression,the tensile strain in the outer region of the bending samples is accommodated to a greater extent due to more pronounced{10-12}twinning and basal slip.As a result,the bending formability of the material at room temperature improves with greater precompression.The variation in microstructure,texture,and bending behavior in relation to the degree of precompression is discussed in detail.展开更多
The combination of graphene with conductive nanoparticles, forming graphene–nanoparticle hybrid materials, offers a number of excellent properties for advanced engineering applications. A novel and simple method was ...The combination of graphene with conductive nanoparticles, forming graphene–nanoparticle hybrid materials, offers a number of excellent properties for advanced engineering applications. A novel and simple method was developed to deposit 10 wt% tin-doped indium tin oxide(ITO) nanoparticles on graphene. The method involved a combination of a solution-based environmentally friendly electroless deposition approach and subsequent vacuum annealing. A stable organic-free solution of ITO was prepared from economical salts of In(NO_3)_3H_2 O and SnCl_4. The obtained ITO nanostructure exhibited a unique architecture, with uniformly dispersed 25–35 nm size ITO nanoparticles, containing only the crystallized In_2O_3 phase. The synthesized ITO nanoparticles–graphene hybrid exhibited very good and reproducible optical transparency in the visible range(more than 85%) and a28.2% improvement in electrical conductivity relative to graphene synthesized by chemical vapor deposition. It was observed that the ITO nanoparticles affect the position of the Raman signal of graphene, in which the D, G, and 2 D peaks were redshifted by 5.65, 5.69, and 9.74 cm^(-1),respectively, and the annealing conditions had no significant effect on the Raman signatures of graphene.展开更多
The ffect of tin-oxide(SnO)nanoparticles,which are obtained by indium-tin-oxide(ITO)treatment,on the p-GaN surface of GaN-based flip-chip blue micro-light-emitting diode(μ-LED)arrays is investigated.A thin Ag layer i...The ffect of tin-oxide(SnO)nanoparticles,which are obtained by indium-tin-oxide(ITO)treatment,on the p-GaN surface of GaN-based flip-chip blue micro-light-emitting diode(μ-LED)arrays is investigated.A thin Ag layer is deposited on the ITO-treated p-GaN surface by sputtering.SnO nanoparticles originate from inho-mogencous Schottly barrier heights(SBHs)at Ag/p-GaN contact.Therefore,efective SBH is reduced,which causes carrier transport into theμ-LED to enhance.10 nm thick ITO-treatedμ-LEDs show better optoelectronic characteristics among fabricated u-LEDs owing to improved ohmic contact and highly reflective p-type reflectors.Basically,SnO nanoparticles help to make good ohmic contact,which results in improved carrier transport intoμ-LEDs and thus results in increased optoelectronic performances.展开更多
基金This work was supported by a National Research Foundation of Korea(NRF)grant funded by the Korean government(MSIP,South Korea)(No.2019R1A2C1085272)the R&D Center for Valuable Recycling(Global-Top R&BD Program)of the Ministry of Environment of Korea(No.2016002220003).
文摘In this study,the texture of a rolled Mg alloy is effectively modified through the application of precompression and subsequent annealing treatment,leading to a remarkable improvement in the bending formability of the alloy at room temperature.Precompression induces lattice reorientation through{10-12}twinning,and annealing treatment reduces the stored strain energy of the precompressed material,which results in the formation of a stable grain structure with two dominant texture components.With an increase in precompression,the tensile strain in the outer region of the bending samples is accommodated to a greater extent due to more pronounced{10-12}twinning and basal slip.As a result,the bending formability of the material at room temperature improves with greater precompression.The variation in microstructure,texture,and bending behavior in relation to the degree of precompression is discussed in detail.
基金supported by the Basic Science Research Program of the National Research Foundation(NRF)of Koreafunded by the Ministry of Education(NRF-2014R1A6A1030419 and NRF-2015R1D1A1A01061005)
文摘The combination of graphene with conductive nanoparticles, forming graphene–nanoparticle hybrid materials, offers a number of excellent properties for advanced engineering applications. A novel and simple method was developed to deposit 10 wt% tin-doped indium tin oxide(ITO) nanoparticles on graphene. The method involved a combination of a solution-based environmentally friendly electroless deposition approach and subsequent vacuum annealing. A stable organic-free solution of ITO was prepared from economical salts of In(NO_3)_3H_2 O and SnCl_4. The obtained ITO nanostructure exhibited a unique architecture, with uniformly dispersed 25–35 nm size ITO nanoparticles, containing only the crystallized In_2O_3 phase. The synthesized ITO nanoparticles–graphene hybrid exhibited very good and reproducible optical transparency in the visible range(more than 85%) and a28.2% improvement in electrical conductivity relative to graphene synthesized by chemical vapor deposition. It was observed that the ITO nanoparticles affect the position of the Raman signal of graphene, in which the D, G, and 2 D peaks were redshifted by 5.65, 5.69, and 9.74 cm^(-1),respectively, and the annealing conditions had no significant effect on the Raman signatures of graphene.
基金National Research Foundation of Korea(NRF-2014R1A6A1030419,NRF-2018R1D1A3A03000779)Korea.Evaluation Institute of Industrial Technology(20004946).
文摘The ffect of tin-oxide(SnO)nanoparticles,which are obtained by indium-tin-oxide(ITO)treatment,on the p-GaN surface of GaN-based flip-chip blue micro-light-emitting diode(μ-LED)arrays is investigated.A thin Ag layer is deposited on the ITO-treated p-GaN surface by sputtering.SnO nanoparticles originate from inho-mogencous Schottly barrier heights(SBHs)at Ag/p-GaN contact.Therefore,efective SBH is reduced,which causes carrier transport into theμ-LED to enhance.10 nm thick ITO-treatedμ-LEDs show better optoelectronic characteristics among fabricated u-LEDs owing to improved ohmic contact and highly reflective p-type reflectors.Basically,SnO nanoparticles help to make good ohmic contact,which results in improved carrier transport intoμ-LEDs and thus results in increased optoelectronic performances.
