arXiv 0803.33682008-03-24cond-mat.mtrl-sci

Semiconductor to metal transition in SWNTs caused by interaction with gold and platinum nanoparticles

Rakesh Voggu, Shrinwantu Paul, Swapan K. Pati, C. N. R. Rao

备注：: 16 pages, 5 figures
发表信息：: 2008 J. Phys.: Condens. Matter 20 215211
DOI：: 10.1088/0953-8984/20/21/215211

英文摘要：

Single-walled carbon nanotubes (SWNTs) have been coated with gold and platinum nanoparticles either by microwave treatment or by the click reaction and the Raman spectra of these SWNT-metal nanoparticle composites have been investigated. Analysis of the G bands in the Raman spectra shows an increase in the proportion of metallic SWNTs on attachment with metal nanoparticles. This conclusion is also supported by the changes observed in the RBM bands. Ab-initio calculations reveal that semiconductor-metal transition occurs in SWNTs due to Columbic charge transfer between the metal nanoparticles and the semiconducting SWNTs.

机构、总结、中文摘要均由AI分析而来，可能存在错误，请以论文正文为准。

阅读原文

阅读 PDF ↗

arXiv 页面 ↗HTML 原文 ↗

本文内容

英文摘要相关论文

机构、总结、中文摘要均由AI分析而来，可能存在错误，请以论文正文为准。

继续探索

相关论文

Metal-Enhanced Fluorescence of Carbon Nanotubes

The photoluminescence (PL) quantum yield of single-walled carbon nanotubes (SWNTs) is relatively low, with various quenching effects by metallic species reported in the literature. Here, we report the first case of metal enhanced fluorescence (MEF) of surfactant-coated carbon nanotubes on nanostructured gold substrates. The photoluminescence quantum yield of SWNTs is observed to be enhanced more than 10-fold. The dependence of fluorescence enhancement on metal-nanotube distance and on surface plasmon resonance (SPR) of the gold substrate for various SWNT chiralities is measured to reveal the m…

2010-10-27cond-mat.mtrl-sci

Quasi-harmonic thermoelasticity of palladium, platinum, copper, and gold from first principles

We calculate the temperature-dependent elastic constants of palladium, platinum, copper and gold within the quasi-harmonic approximation using a first-principles approach and evaluating numerically the second derivatives of the Helmholtz free-energy with respect to strain at the minimum of the free-energy itself. We find an overall good agreement with the experimental data although the anomalies of palladium and platinum reported at room temperature are not reproduced. The contribution of electronic excitations is also investigated: we find that it is non-negligible for the $C_{44}$ elastic co…

2021-09-01cond-mat.mtrl-scicond-mat.other

Ultrafast electron dynamics in platinum and gold thin films driven by optical and terahertz fields

We investigate the ultrafast electron dynamics triggered by terahertz and optical pulses in thin platinum and gold films by probing their transient optical reflectivity. The response of the platinum film to an intense terahertz pulse is similar to the optically-induced dynamics of both films and can be described by a two-temperature model. Surprisingly, gold can exhibit a much smaller terahertz pulse-induced reflectivity change and with opposite sign. For platinum, we estimate a 20% larger electron-phonon coupling for the terahertz-driven dynamics compared to the optically-induced one, which w…

2021-08-19cond-mat.mtrl-sciphysics.app-phphysics.optics

Suspension of Nanoparticles in SU-8 and Characterization of Nanocomposite Properties

Gold nanospheres, single wall carbon nanotubes (SWNT), and diamonoids were phyically incorporated into the negative photoresist SU-8. the mixtures were spin cast onto silicon or aluminium coated silicon wafers. ASTM standard D638 tensile specimens were lithographically patterned in the materials and then released from the substrate using Microchem'Omnicoat or an anodic metal dissolution process. the residual stresses, elastic moduli, and viscosity of the SU-8. Resistivity measurements of SU-8/SWNT nanocomposites were also investigates. We found the effective modulus and viscosity of the SU-8 t…

2007-08-14cond-mat.mtrl-sci

Carbon nanotubes decorated with gold, platinum and rhodium clusters by injection of colloidal solutions into the post-discharge of a RF atmospheric plasma

In this paper, we present a new, simple, robust and efficient technique to decorate multi-wall carbon nanotubes (MWCNT) with metal nanoparticles. As case studies, Au, Pt and Rh nanoparticles are grafted onto MWCNTs by spraying a colloidal solution into the post-discharge of an atmospheric argon or argon/oxygen RF plasma. The method that we introduce here is different from those usually described in the literature, since the treatment is operated at atmospheric pressure, allowing the realization in only one step of the surface activation and the deposition processes. We demonstrate experimental…

2016-05-02cond-mat.mes-hallcond-mat.mtrl-sci

Binding energies and electronic structures of adsorbed titanium chains on carbon nanotubes

We have studied the binding energies and electronic structures of metal (Ti, Al, Au) chains adsorbed on single-wall carbon nanotubes (SWNT) using first principles methods. Our calculations have shown that titanium is much more favored energetically over gold and aluminum to form a continuous chain on a variety of SWNTs. The interaction between titanium and carbon nanotube significantly modifies the electronic structures around Fermi energy for both zigzag and armchair tubes. The delocalized 3d electrons from the titanium chain generate additional states in the band gap regions of the semicondu…

2002-02-08cond-mat.mtrl-sci

更多相关论文收起更多论文

Tunable electrical transport through annealed monolayers of monodisperse cobalt-platinum nanoparticles

We synthesized monodisperse cobalt-platinum nanoparticles Co(0.14-0.22)Pt(0.86-0.78) of 9 nm in diameter by colloidal chemistry methods and deposited them by the Langmuir-Blodgett technique as highly ordered monolayers onto substrates with e-beam defined gold electrodes. Upon annealing we observe an increase of conductivity over more than 4 orders of magnitude. A first attempt of explanation of this unanticipated effect, a nanoparticle displacement, could not be confirmed for annealing temperatures below 400C. A second approach, a carbonization of the ligands, however, could be confirmed by Ra…

2012-01-05cond-mat.mtrl-sci

Contact Resistance Study of Various Metal Electrodes with CVD Graphene

In this study, the contact resistance of various metals to chemical vapour deposited (CVD) monolayer graphene is investigated. Transfer length method (TLM) structures with varying widths and separation between contacts have been fabricated and electrically characterized in ambient air and vacuum condition. Electrical contacts are made with five metals: gold, nickel, nickel/gold, palladium and platinum/gold. The lowest value of 92 Ωμm is observed for the contact resistance between graphene and gold, extracted from back-gated devices at an applied back-gate bias of -40 V. Measurements carried ou…

2022-11-22cond-mat.mtrl-sci

Topological States on the Gold Surface

Gold surfaces host special electronic states that have been understood as a prototype of Shockley surface states (SSs). These SSs are commonly employed to benchmark the capability of angle-resolved photoemission spectroscopy (ARPES) and scanning tunneling spectroscopy. We find that these Shockley SSs can be reinterpreted as topologically derived surface states (TDSSs) of a topological insulator (TI), a recently discovered quantum state. Based on band structure calculations, the Z2 topological invariant can be well defined to characterize the nontrivial features of gold that we detect by ARPES.…

2015-04-08cond-mat.mes-hallcond-mat.mtrl-sci

Mechanical modulation of single-electron tunneling through molecular-assembled metallic nanoparticles

We present a microscopic study of single-electron tunneling in nanomechanical double-barrier tunneling junctions formed using a vibrating scanning nanoprobe and a metallic nanoparticle connected to a metallic substrate through a molecular bridge. We analyze the motion of single electrons on and off the nanoparticle through the tunneling current, the displacement current and the charging-induced electrostatic force on the vibrating nanoprobe. We demonstrate the mechanical single-electron turnstile effect by applying the theory to a gold nanoparticle connected to the gold substrate through alkan…

2004-07-26cond-mat.mes-hallcond-mat.mtrl-sci

Magnetic anisotropies of late transition metal atomic clusters

We analyze the impact of the magnetic anisotropy on the geometric structure and magnetic ordering of small atomic clusters of palladium, iridium, platinum and gold, using Density Functional Theory. Our results highlight the absolute need to include self-consistently the spin orbit interaction in any simulation of the magnetic properties of small atomic clusters, and a complete lack of universality in the magnetic anisotropy of small-sized atomic clusters.

2007-06-13cond-mat.mtrl-scicond-mat.other

在具有平带和拓扑边缘态的金属-无机框架中实现二维Lieb晶格

Realization of a Two-Dimensional Lieb Lattice in a Metal-Inorganic Framework with Flat Bands and Topological Edge States

本研究通过计算设计与分子束外延技术在金基底上成功合成了克服结构不稳定性的二维Pt-P Lieb晶格，验证了其平带结构并预测了由自旋-轨道耦合诱导的拓扑Dirac边缘态，为金属-无机框架原子晶格及强关联拓扑相研究开辟了新前景。

2024-04-29cond-mat.mtrl-sciphysics.app-ph