Single-electron tunneling at room temperature in cobalt nanoparticles

Abstract

We report on the observation of the Coulomb blockade with Coulomb staircases at room temperature in cobalt nanoparticles, with sizes ranging between 1 and 4 nm. A monolayer of these particles is supported by a thin 1–2 nm thick Al2O3 film, deposited on a smooth Au(111) surface. The local electrical transport on isolated Co clusters was investigated with a scanning tunneling microscope (STM). The tunnel contact of the STM tip allowed us to observe single-electron tunneling in the double barrier system STM-tip/Co/Al2O3/Au. Very high values of the Coulomb blockade of up to 1.0 V were reproducibly measured at room temperature on different particles with this setup. The current–voltage characteristics fit well by simulations based on the orthodox theory of single-electron tunneling.

Single electron tunneling and manipulation of nanoparticles on surfaces at room temperature

“…4(b) of aggregated Au-NPs reveals sufficient electric isolation among neighboring particles due to the thiol modification. Such isolation was difficult to achieve in the past, e.g., in Co clusters supported by high dielectric Al 2 O 3 film [17]. This electric isolation among neighboring NPs is especially desired in the construction of single-electron devices, e.g., floating gate devices.…”

“…Scanning tunneling microscopy (STM) and spectroscopy (STS) have proven to be an accurate test platform for SET and conductance/capacitance measurements [6][7][8]10,12,16,17]. STM not only is able to image NPs with high resolution, but also can perform current-distance (I-Z) and current-voltage (I-V) spectroscopy measurements.…”

Molecular dynamics simulation of gold cluster growth during sputter deposition

“…The variety of technological applications based on nanocomposites can be found in, e. g., electronics [1][2][3][4], plasmonics [5,6], food packaging [7] and medicine [8,9]. While various types of materials are present in synthetic and natural nanocomposites, metal-polymer nanocomposites are of specific interest as they are promising candidates for the fabrication of materials with tailored magnetic, electronic and optical properties [10][11][12][13][14][15][16] at low cost.…”

Gundlach oscillations and Coulomb blockade of Co nanoislands on MgO/Mo(100) investigated by scanning tunneling spectroscopy at 300 K

“…This is probably due to a large coupling of the cluster charge to the phonons of the ionic insulator [30]. Notice that Coulomb oscillations of metal clusters on insulating thin films have rarely been observed at room temperature so far [8,31,32].…”