The interface electronic structure of thiol terminated molecules on cobalt and gold surfaces

Caruso, Anthony N.; Wang, Ligen; Jaswal, S. S.; Tsymbal, Evgeny Y.; Dowben, Peter A.

doi:10.1007/s10853-006-0362-7

Cited by 26 publications

(26 citation statements)

References 92 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…It was not precipitated after centrifugation for 10 min at 3500 rpm. The success of ligand-exchanged CoFe 2 O 4 nanoparticles using 11-MUA can be explained by the binding of the carboxylate end to iron atoms and the mercapto end to cobalt atoms [9][10][11][12][13][14]. These CoFe 2 O 4 nanoparticles and their dispersions in water have great potential in biomagnetic applications.…”

Section: Resultsmentioning

confidence: 99%

Heat generation of aqueously dispersed CoFe2O4 nanoparticles as heating agents for magnetically activated drug delivery and hyperthermia

Kim

Nikles

Johnson

et al. 2008

Journal of Magnetism and Magnetic Materials

307

138

View full text Add to dashboard Cite

Section: Resultsmentioning

confidence: 99%

Heat generation of aqueously dispersed CoFe2O4 nanoparticles as heating agents for magnetically activated drug delivery and hyperthermia

Kim

Nikles

Johnson

et al. 2008

Journal of Magnetism and Magnetic Materials

307

138

View full text Add to dashboard Cite

“…Despite the considerable interest in SAMs on ferromagnetic surfaces, for both fundamental reasons and applied purposes, the investigation of the structure of monolayers and how they influence magnetic properties has been limited so far to very few, mainly theoretical, studies [21][22][23]. In this work, we have deposited octanethiols [CH 3 (CH 2 ) 6 CH 2 SH] and dodecanethiols [CH 3 (CH 2 ) 10 CH 2 SH] under ultra-high vacuum (UHV) conditions on thin Co films supported on a Au(111) substrate, as shown schematically in figure 1(a).…”

Section: Introductionmentioning

confidence: 99%

Change of cobalt magnetic anisotropy and spin polarization with alkanethiolates self-assembled monolayers

et al. 2015

View full text Add to dashboard Cite

We demonstrate that the deposition of a self-assembled monolayer of alkanethiolates on a 1 nm thick cobalt ultrathin film grown on Au(111) induces a spin reorientation transition from in-plane to outof-plane magnetization. Using ab initio calculations, we show that a methanethiolate layer changes slightly both the magnetocrystalline and shape anisotropy, both effects almost cancelling each other out for a 1 nm Co film. Finally, the change in hysteresis cycles upon alkanethiolate adsorption could be assigned to a molecular-induced roughening of the Co layer, as shown by STM. In addition, we calculate how a methanethiolate layer modifies the spin density of states of the Co layer and we show that the spin polarization at the Fermi level through the organic layer is reversed as compared to the uncovered Co. These results give new theoretical and experimental insights for the use of thiol-based self-assembled monolayers in spintronic devices.

show abstract

“…Additional states at this energy are a result of mixing of the electronic states of thiolates with those of the Au core (21,22).…”

mentioning

confidence: 99%

Identification of parameters through which surface chemistry determines the lifetimes of hot electrons in small Au nanoparticles

Aruda

Tagliazucchi

Sweeney

et al. 2013

Proc. Natl. Acad. Sci. U.S.A.

View full text Add to dashboard Cite

This paper describes measurements of the dynamics of hot electron cooling in photoexcited gold nanoparticles (Au NPs) with diameters of ∼3.5 nm, and passivated with either a hexadecylamine or hexadecanethiolate adlayer, using ultrafast transient absorption spectroscopy. Fits of these dynamics with temperature-dependent Mie theory reveal that both the electronic heat capacity and the electron-phonon coupling constant are larger for the thiolated NPs than for the aminated NPs, by 40% and 30%, respectively. Density functional theory calculations on ligand-functionalized Au slabs show that the increase in these quantities is due to an increased electronic density of states near the Fermi level upon ligand exchange from amines to thiolates. The lifetime of hot electrons, which have thermalized from the initial plasmon excitation, increases with increasing electronic heat capacity, but decreases with increasing electronphonon coupling, so the effects of changing surface chemistry on these two quantities partially cancel to yield a hot electron lifetime of thiolated NPs that is only 20% longer than that of aminated NPs. This analysis also reveals that incorporation of a temperaturedependent electron-phonon coupling constant is necessary to adequately fit the dynamics of electron cooling. two-temperature model | dissipation T his paper describes an observed dependence of two physical properties-the electronic heat capacity and the electronphonon coupling magnitude-of small (diameter of ∼3.5 nm), completely absorptive plasmonic gold nanoparticles (Au NPs) on the surface chemistry of the NPs. The electronic heat capacity, quantified by the coefficient γ, is the amount of energy required to change the temperature of a population of electrons in the NP. The magnitude of the electron-phonon coupling, quantified by the coefficient g, is a measure of the rate of exchange of energy between the electrons and the lattice. Upon photoexcitation of the Au NPs at the absorption maximum of their plasmon resonance, the plasmonic electron oscillation in the NPs rapidly decoheres to form a thermally equilibrated population of hot electrons (1-8). Within the commonly used "two-temperature model (2TM)," the rate of subsequent cooling of these electrons is dictated by the initial electronic temperature of the particle and the efficiency of dissipation of electronic energy into available vibrational modes. These properties, in turn, depend on the electronic heat capacity of the system and the magnitude of electron-phonon coupling. Our observed dependence of the coefficients γ and g on the chemical structure of the organic adlayer therefore implies that electronic states that participate in the electron cooling process are not only those of the gold lattice, but also orbitals at the metal-organic interface-that is, the surface chemistry of the NPs influences the rate of hot electron cooling.Interest in using metal and semiconductor NPs as optical and/or electronic components within energy conversion systems (9, 10) has inspired studies of ene...

show abstract

The interface electronic structure of thiol terminated molecules on cobalt and gold surfaces

Cited by 26 publications

References 92 publications

Heat generation of aqueously dispersed CoFe2O4 nanoparticles as heating agents for magnetically activated drug delivery and hyperthermia

Heat generation of aqueously dispersed CoFe2O4 nanoparticles as heating agents for magnetically activated drug delivery and hyperthermia

Change of cobalt magnetic anisotropy and spin polarization with alkanethiolates self-assembled monolayers

Identification of parameters through which surface chemistry determines the lifetimes of hot electrons in small Au nanoparticles

Contact Info

Product

Resources

About