Fabrication of Stable Metal Films on the Surface of Self‐Assembled Monolayers

Abstract

strongly connected grains and without AEC phases by a simple electrophoretic deposition technique. It is therefore thought that the present results may provide a significant breakthrough for the high-T c superconducting film and wire fabrication industries. ExperimentalPristine Bi 2 Sr 2 CaCu 2 O 8+y (Bi2212) was prepared by a conventional solid-state reaction [10±14]. As a secondary precursor, HgI 2 intercalates were synthesized through hard±soft acid±base reactions, as documented in our previous reports [10±14]. To intercalate (PyC 12 H 25 ) 2 -HgI 4 (where Py = pyridine), the HgI 2 -intercalates were mixed with a three-times molar excess of Py-C 12 H 25 I, and then a few drops of analytical grade (³ 99.8 % purity) acetone were added to the mixture. Each of the resulting mixtures was reacted in a closed ampoule at 50±60 C for 48 h. Finally, the dark-brown gel-like products were washed with acetone to remove the excess organic salts on the crystal surfaces. Exfoliation of the bisalkylpyridinium tetraiodomercurate [(Py-C 12 H 25 ) 2 HgI 4 ] intercalates was carried out by sonicating them at 28 kHz in acetone solvent, which was kept in an ice bath to prevent overheating of the suspension. For the fabrication of superconducting films and microwires, the exfoliated Bi2212 nanosheets in acetone solvent were electrophoretically deposited onto Ag substrates with a power-source meter (Keithley 2400) using a Pt plate (2 cm 5 cm) as a counter-electrode. As-deposited films and wires were subsequently heated at 840 C for 12 h.

Electronic structure and polymerization of a self-assembled monolayer with multiple arene rings

“…3 Among other approaches, electron beam irradiation leads to the cross linking or quasi ͑two-dimensional͒ polymerization of ͓1,1Ј;4Ј,1Љ-terphenyl͔-4,4Љ-dimethanethiol ͑TPDMT͒, making the SAM layer a network of chemically linked TPDMT molecules. [7][8][9] Cross-linked SAM layers provide an effective barrier for the penetration of a metal adsorbate. The cross linking makes possible the formation of the top electrode and the cross-linked SAM layers can then play the role of an insulating layer between this electrode and the bottom gold electrode.…”

Radiation-induced decomposition of the metal-organic molecule Bis(4-cyano-2,2,6,6-tetramethyl-3,5-heptanedionato)copper(II)

“…Generally, except possibly at the very initial exposures to radiation, since enhancement of the substrate Co 3d bands nearest to the Fermi level, with radiation exposure, is not apparent in Fig. 2, the irradiation modification is not a result of significant molecular desorption, as may be the case with similar experiments of nickelocene adsorbed on Ag (1 0 0) 00 -dimethanethiol films [7][8][9][10], some dehydrogenation is implicated. These binding energy shifts of the photoemission features could indicate a formation of a smaller band gap between the highest occupied (HOMO) and lowest unoccupied (LUMO) molecular orbitals.…”

“…As with the case of adsorbed [1,1 0 ;4 0 ,1 00 -terphenyl]-4,4 00 -dimethanethiol films [7][8][9][10], and other molecular adlayers, extensive irradiation leads to fragmentation beyond simple dehydrogenation of peripheral hydrogens. As seen in Fig.…”

“…In the case of monomolecular insulator [1,1 0 ;4 0 ,1 00 -terphenyl]-4,4 00 -dimethanethiol films, irradiation-induced modifications lead to cross-linking of the terphenyldimethanethiol molecules within the film, which results in a quasi-polymeric material with improved dielectric properties [7][8][9][10]. While irradiation-induced modifications tend to lead to decomposition and desorption processes in aliphatic organic adlayers, cross-linking is the dominant effect in the aromatic ones, resulting in a quasi-polymerization of the monomolecular film [11][12][13].…”

“…While irradiation-induced modifications tend to lead to decomposition and desorption processes in aliphatic organic adlayers, cross-linking is the dominant effect in the aromatic ones, resulting in a quasi-polymerization of the monomolecular film [11][12][13]. Such polymer-like but ordered layers provide the possibility of using the organic self assembled monolayers as ultrathin insulating layers in electronic and spintronic devices [7][8][9][10][11][12][13].…”