Noble metal nanoparticles exhibit unique surface plasmon resonance dependent optical properties.On this basis,gold nanoparticles(AuNPs)encapsulated in metal–organic frameworks(MOFs)can form AuNPs@MOFs composites to m...Noble metal nanoparticles exhibit unique surface plasmon resonance dependent optical properties.On this basis,gold nanoparticles(AuNPs)encapsulated in metal–organic frameworks(MOFs)can form AuNPs@MOFs composites to modulate the optical properties of fluorescent molecules,which is less reported.In this paper,based on the fluorescence enhancement effect of AuNPs on 2-(2-hydroxyphenyl)-1H-benzimidazole(HPBI)molecules,zeolitic imidazolate framework-8(ZIF-8)crystals with structural stability were introduced.AuNPs@ZIF-8 exhibited a significantly pronounced fluorescence enhancement of the HPBI molecules.In addition,by comparing the fluorescence characteristics of the HPBI molecules adsorbed on AuNPs@ZIF-8 and those captured in AuNPs@ZIF-8,we found that the ZIF-8 can act as a spacer layer with highly effective near-field enhancement.All our preliminary results shed light on future research on the composite structures of noble metal particles and MOFs for fluorescent probes and sensing applications.展开更多
利用真空热蒸发的方法,在云母片上制备分子层数可控的锌卟啉(ZnTPP)分子薄膜.随着分子层数的增多,ZnTPP薄膜的光致荧光(Photoluminescence,PL)光谱从单体特征渐变为二聚体特征;原子力显微镜(Atomic Force Microscope,AFM)的图像中,ZnTP...利用真空热蒸发的方法,在云母片上制备分子层数可控的锌卟啉(ZnTPP)分子薄膜.随着分子层数的增多,ZnTPP薄膜的光致荧光(Photoluminescence,PL)光谱从单体特征渐变为二聚体特征;原子力显微镜(Atomic Force Microscope,AFM)的图像中,ZnTPP分子团簇成纳米尺度的岛状结构,非真空环境导致纳米岛进一步聚集,从而使二聚体特征峰荧光强度激增;样品荧光寿命表明在非真空环境下分子的二聚体衰减通道比例显著增加.展开更多
The influence of surface/interface roughness on the magnetic properties of Fe/Ni multilayers is investigated.Two methods are employed to tune the film roughness:one varies the substrate temperature,and the other pre-d...The influence of surface/interface roughness on the magnetic properties of Fe/Ni multilayers is investigated.Two methods are employed to tune the film roughness:one varies the substrate temperature,and the other pre-deposits a Ag underlayer on the MgO substrate.For films with higher roughness,a marked rise in coercivity is observed.Three factors are discussed to be mainly responsible for the coercivity rise,involving the formation of pinholes,the reduction of exchange coupling between Fe and Ni layers,and Fe-Ni alloying at interfaces.展开更多
[Fe/Ni ] N multilayered 结构在单个水晶的 MgO 底层上取向附生地成长。由于 Fe 和 Ni 和强壮的紧张的磁性的容易的轴的不同方向，大 anisotropy 分散被假定。根据层模型的意见，因为联合的交换， Fe 和 Ni 层的磁化不能跟随每容易的...[Fe/Ni ] N multilayered 结构在单个水晶的 MgO 底层上取向附生地成长。由于 Fe 和 Ni 和强壮的紧张的磁性的容易的轴的不同方向，大 anisotropy 分散被假定。根据层模型的意见，因为联合的交换， Fe 和 Ni 层的磁化不能跟随每容易的轴，然后 anisotropies 被平均。有效 anisotropy 的减小与周期的厚度的减少提高。因此， coercivity [Fe/Ni ] 有减少的周期的厚度的 N multilayers 还原剂。[从作者抽象]展开更多
Thin Mn（2 nm）/Al（2 nm） bilayers serving as buffer layers have been prepared prior to the deposition of MnAl films. The ferromagnetic T-phase forms in the buffer layers at an optimum substrate temperature. As a tem...Thin Mn（2 nm）/Al（2 nm） bilayers serving as buffer layers have been prepared prior to the deposition of MnAl films. The ferromagnetic T-phase forms in the buffer layers at an optimum substrate temperature. As a template it induces the growth of following MnAl film. Compared with the case of film without buffer layer, the growth of nonferromagnetic phase is suppressed and the structural and magnetic properties of MnAl film are improved. Weak dipolar inter-grain coupling is revealed in the MnAl film, and the magnetic reversal process is dominated by magnetic moment rotation.展开更多
The influences of an Fe cap layer on the structural and magnetic properties of FePt/Fe bi-layers are investigated. Compared with single FePt alloy films, a thin Fe layer can affect the crystalline orientation and impr...The influences of an Fe cap layer on the structural and magnetic properties of FePt/Fe bi-layers are investigated. Compared with single FePt alloy films, a thin Fe layer can affect the crystalline orientation and improve the chemical ordering of L10 FePt films. Moreover, the coercivity increases when a thin Fe layer covers the FePt layer. Beyond a critical thickness, however, the Fe cover layer quickens the magnetization reversal of Fe49Pt51/Fe bi-layers by their exchange coupling.展开更多
A series of Co/Alq3 granular film samples are prepared using co-evaporating technique. The microstructures and magnetic properties are investigated. The Kerr spectra and optical constants of Cox（Alq3）1-x （0.19 ≤ x...A series of Co/Alq3 granular film samples are prepared using co-evaporating technique. The microstructures and magnetic properties are investigated. The Kerr spectra and optical constants of Cox（Alq3）1-x （0.19 ≤ x ≤ 1） granular films are measured using a magneto-optical Kerr spectrometer and a spectroscopic ellipsometer in the 1.5-4.5 eV photon energy range. The Kerr rotation reaches the maximum value of 0.5° in the x = 0.65 sample. The relationship between enhanced Kerr rotation and optical constants is discussed, and the concentration dependence of MOKE spectra is also investigated.展开更多
文摘Noble metal nanoparticles exhibit unique surface plasmon resonance dependent optical properties.On this basis,gold nanoparticles(AuNPs)encapsulated in metal–organic frameworks(MOFs)can form AuNPs@MOFs composites to modulate the optical properties of fluorescent molecules,which is less reported.In this paper,based on the fluorescence enhancement effect of AuNPs on 2-(2-hydroxyphenyl)-1H-benzimidazole(HPBI)molecules,zeolitic imidazolate framework-8(ZIF-8)crystals with structural stability were introduced.AuNPs@ZIF-8 exhibited a significantly pronounced fluorescence enhancement of the HPBI molecules.In addition,by comparing the fluorescence characteristics of the HPBI molecules adsorbed on AuNPs@ZIF-8 and those captured in AuNPs@ZIF-8,we found that the ZIF-8 can act as a spacer layer with highly effective near-field enhancement.All our preliminary results shed light on future research on the composite structures of noble metal particles and MOFs for fluorescent probes and sensing applications.
文摘利用真空热蒸发的方法,在云母片上制备分子层数可控的锌卟啉(ZnTPP)分子薄膜.随着分子层数的增多,ZnTPP薄膜的光致荧光(Photoluminescence,PL)光谱从单体特征渐变为二聚体特征;原子力显微镜(Atomic Force Microscope,AFM)的图像中,ZnTPP分子团簇成纳米尺度的岛状结构,非真空环境导致纳米岛进一步聚集,从而使二聚体特征峰荧光强度激增;样品荧光寿命表明在非真空环境下分子的二聚体衰减通道比例显著增加.
基金Supported by the National Natural Science Foundation of China under Grant Nos 51071046,61078030,11074046,11174056,11274113the National Basic Research Program of China(2009CB929201)the Characterization Facility,University of Minnesota,a member of the NSF-funded Materials Research Facilities Network(www.mrfn.org)via the NSF MRSEC program under award number DMR-0819885.
文摘The influence of surface/interface roughness on the magnetic properties of Fe/Ni multilayers is investigated.Two methods are employed to tune the film roughness:one varies the substrate temperature,and the other pre-deposits a Ag underlayer on the MgO substrate.For films with higher roughness,a marked rise in coercivity is observed.Three factors are discussed to be mainly responsible for the coercivity rise,involving the formation of pinholes,the reduction of exchange coupling between Fe and Ni layers,and Fe-Ni alloying at interfaces.
基金Supported by the National Natural Science Foundation of China under Grant Nos 60490290, 60678008, 10604016, 50771032 and 50771033, the National Basic Research Program of China （2009CB929201）.
We-thank Professor Wang Jian-Ping for constructive discussion. The Characterization Facility and Institute of Rock Magnetism Facilities are acknowledged for structural and magnetic measurements.
文摘[Fe/Ni ] N multilayered 结构在单个水晶的 MgO 底层上取向附生地成长。由于 Fe 和 Ni 和强壮的紧张的磁性的容易的轴的不同方向，大 anisotropy 分散被假定。根据层模型的意见，因为联合的交换， Fe 和 Ni 层的磁化不能跟随每容易的轴，然后 anisotropies 被平均。有效 anisotropy 的减小与周期的厚度的减少提高。因此， coercivity [Fe/Ni ] 有减少的周期的厚度的 N multilayers 还原剂。[从作者抽象]
基金Supported by the National Natural Science Foundation under Grant Nos 60490290, 10404019, and 10374019, the Science and Technology Committee of Shanghai under Grant No 04D214001, and the Ministry of Education of China.
基金Project supported by the National Natural Science Foundation of China (Grant Nos. 60490290, 60678008, 10604016, 50771032,and 50771033)the National Basic Research Program of China (Grant No. 2009CB929201)
文摘Thin Mn（2 nm）/Al（2 nm） bilayers serving as buffer layers have been prepared prior to the deposition of MnAl films. The ferromagnetic T-phase forms in the buffer layers at an optimum substrate temperature. As a template it induces the growth of following MnAl film. Compared with the case of film without buffer layer, the growth of nonferromagnetic phase is suppressed and the structural and magnetic properties of MnAl film are improved. Weak dipolar inter-grain coupling is revealed in the MnAl film, and the magnetic reversal process is dominated by magnetic moment rotation.
基金Project supported by the National Natural Science Foundation of China (Grant Nos 60490290,60678008 and 50771032)the National Basic Research Program of China (Grant No 2009CB929201)the Science Foundation of the Science and Technology Committee of Shanghai (Grant No 06DJ14007)
文摘The influences of an Fe cap layer on the structural and magnetic properties of FePt/Fe bi-layers are investigated. Compared with single FePt alloy films, a thin Fe layer can affect the crystalline orientation and improve the chemical ordering of L10 FePt films. Moreover, the coercivity increases when a thin Fe layer covers the FePt layer. Beyond a critical thickness, however, the Fe cover layer quickens the magnetization reversal of Fe49Pt51/Fe bi-layers by their exchange coupling.
基金Supported by the National Natural Science Foundation of China under Grant 60501002.
文摘A series of Co/Alq3 granular film samples are prepared using co-evaporating technique. The microstructures and magnetic properties are investigated. The Kerr spectra and optical constants of Cox（Alq3）1-x （0.19 ≤ x ≤ 1） granular films are measured using a magneto-optical Kerr spectrometer and a spectroscopic ellipsometer in the 1.5-4.5 eV photon energy range. The Kerr rotation reaches the maximum value of 0.5° in the x = 0.65 sample. The relationship between enhanced Kerr rotation and optical constants is discussed, and the concentration dependence of MOKE spectra is also investigated.
