Passivation of cobalt nanocluster assembled thin films with hydrogen

Abstract

The effect of hydrogen passivation on bare and Pd capped cobalt nanocluster assembled thin films was studied with Rutherford backscattering spectrometry (RBS) and magnetic force microscopy (MFM) after exposure to ambient conditions. The nanoclusters are produced in a laser vaporization cluster source in which the helium carrier gas was mixed with hydrogen. RBS revealed that oxidation of the Co nanoclusters is considerably reduced by the presence of hydrogen during cluster formation. The capping did not modify the influence of the passivation. The hydrogen passivation method is especially effective in cases when capping of the films is not desirable, for example for magnetic studies. Clear differences in the magnetic domain structures between hydrogen passivated and non-passivated Co nanocluster films were demonstrated by MFM and are attributed to a difference in inter-cluster magnetic interaction, which is critically depending on the CoO content. The hydrogen passivation method may be used to tailor and stabilize properties of nanocluster assembled thin films.

Exploration on Electronic Properties of Self-Assembled Indium Nitrogen Nanosheets and Nanowires by a Density Functional Method

“…In order to develop future novel nanomaterials, the semiconducting nanostructures of materials play key roles because they uncover unique behaviors and possess widespread potential applications in energy materials and electronic and optoelectronic nanodevices [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18]. In particular, self-assembled nanowires, which can address fundamental issues related to dimensionality, have widespread applications in optoelectronic and nano-electronic devices.…”

“…In particular, self-assembled nanowires, which can address fundamental issues related to dimensionality, have widespread applications in optoelectronic and nano-electronic devices. The interesting properties of size-specific self-assembled nanosheets or clusterassembled nanowires [6,8,12] allow new nanomaterials and nanodevices to be generated that can be applied to different nanoscience fields [1][2][3]6,8,[10][11][12][13][14][15][16][17][18][19][20][21]. The individual properties of the magic stable cluster being used as a building unit for these self-assembled nanosheets, nanowires, or nanomembranes are actually maintained.…”

“…However, these self-assembled nanostructures hold unique electronic properties and may acquire different properties or functions that differ from those observed for macroscale counterpart materials. The specific geometrical forms and electronic properties of self-assembled nanostructures have very important potential applications in energy nanomaterials and electronic nanomaterials [1,[10][11][12][13][14][15][16][17][18][19][20][21]. Thus, semiconductor structured nanomaterials hold the potential to promote advancements in the rapidly growing technological fields.…”

“…It has been found that metal oxides (ZnO, Al 2 O 3 , and MgO), metal sulfides (Cu 3 S 3 , CdS, and ZnS), and transition metal nitrides (GaN, AlN, and InN), together with their cluster-assembled nanomaterials, are of very high interest and have been widely investigated [1][2][3][4][5][7][8][9][10][11][12][13][14][15][16][17][19][20][21], and the possible geometries and energy gaps of inner hollow semiconductor (GaN) 2n nanocages have been confirmed [21]. It has been found that the stable GaN and InN nanocages are good semiconductor materials with stronger electron mobility, which is consistent with experimental values [9,11,13,14]. Moreover, the relative stabilities of nano-size (InN) 2n and (CdS) 2n (n = 5-27) clusters have been studied, and the photon-to-current conversion efficiency related to the energy conversion of inner hollowed nano-size Cd 2n S 2n (n = 5-27) clusters has been discussed [7,9].…”

Fabrication of Silver Nanoparticles Using a Gas Phase Nanocluster Device and Preliminary Biological Uses

“…Our group has, in previous work, used NPs solely for solid-state physics topics, such as magnetism, superconductivity, and hydrogen storage [16,17,18]. This incursion into this specific topic of mixing biological response and NPs is due to the relevance we see in this unfolding field.…”