Recently, advances in the technological development of ion sources and ion acceleration, the use of eV to GeV atomic, molecular and cluster ions has become possible in materials research for deposition, surface modification, new materials formation, surface analysis, etc. Among the ion beam techniques, ion implantation is a unique method for altering the surface properties of materials. Here, some studies on ion implantation with ceramic materials are reviewed in short. Some recent studies on ion implantation with metals and rare earth elements for optical and optoelectronic applications are also shown.
While there are stringent performance criteria, as well as competition from resonant and non-resonant semiconductor quantum dot materials, organic materials, and other glass systems, nanometer dimension metal particle glass composites have some properties that may make them viable candidates for all optical switching networks: large third order nonlinear response, picosecond switching and relaxation times, thermal and chemical stability, high laser damage threshold, and low two photon absorption. Metal nanocluster composites can be fabricated by ion implantation. It has been shown that particle size can be controlled by the total dose, current density, and substrate temperature. The depth of the implanted particles can be controlled by the implantation energy. The formation and size of these colloids when formed by ion implantation are highly dependent upon the composition of the substrate. Post implantation processing can subsequently be used to alter the size and size distribution of the colloids. Sequential ion implantation can be used to extend the ion implantation method of forming metal nanocluster glass composites by allowing the formation of multi-component particles in glass. This technique has been demonstrated to significantly alter the composition of the metal particles formed. As a consequence the formation of multi-component nanoclusters results in changes in both the linear and nonlinear optical properties of the composite that are not possible with single element colloids. Here we review the formation and optical properties of multi-component nanoclusters formed by sequential implantation in silica compared to their single element counterparts. In this paper we focus on work done by the authors on the following systems; Ag/Sb, Ag/Cu and Ag/Cd.
Recently, ion implantation has strongly stimulated efforts for the creation of high performance wide gap oxide materials. This article briefly reviews our recent works on the creation of wide gap oxide glassy and amorphous materials with an optoelectronic function by ion implantation along with the background and expectation for a new extension utilizing properties of photo-active structural defects produced by implantation. The topics cover nanometer-sized colloid embedded glasses for nonlinear optical materials, transparent amorphous oxides with metallic conduction, and fast proton-conducting glasses.
In this article, we first emphasize several interesting aspects of granular materials. After overviewing electrical conductivity, such as electrical resistivity and magnetoresistance (MR), in ferromagnetic metals and alloys, we review MR, magnetic properties and structure of granular Fe/Cu films produced by the ion-cluster-beam method. These films reveal giant MR (GMR) at low temperature without post-annealing. The non-saturation behavior of GMR and the saturation behavior of magnetization against applied fields demonstrate that conduction electron scattering by magnetic moments at the cluster-matrix interface plays an important role of GMR. The nanometric scale compositional and structural imhomogeneity, and atomic scale structure of these films are discussed using the results of small angle X-ray scattering and extended X-ray absorption fine structure spectra.
This paper describes attempts to synthesize thin SiC films by using dual ion beam deposition at non-elevated temperature. SiC is one of the most widely investigated materials because it has many attractive properties. Dual ion beam deposition in which two argon ion beams were employed, with one sputtering a silicon target to provide a Si flux, and the other bombarding the substrate on which films grow. Methane and ethene gas were introduced into the system with a partial pressure up to 1.8 × 10-2 Pa. The characteristics of resultant films were analyzed by Rutherford backscattering spectroscopy, Knoop micro hardness test. Films containing a different C:Si ratio, including stoichiometric SiC, have been successfully deposited at a rate-0.1nm/s. In addition to C and Si, films contain other atomic species present in the precursor molecules together with reasonably large concentrations of the ion bombardment species, Ar.
IBIEC (Ion Beam Induced Epitaxial Crystallization) is one of the methods of SPEC (Solid Phase Epitaxial Crystallization) and is characterized by its low temperature crystallization and low thermal activation energy relative to thermally induced SPEC. IBIEC has been investigated for many years from the view of interest in its mechanism concerned with ion-solid interaction and application to a low temperature SPEC process particularly in Si. Recently, this technique has been tried to apply to many different kinds of materials such as compound semiconductors (GaAs, BP, InP and GeSi), carbide (SiC), silicides (NiSi2 and CoSi2) and even oxides (Al2O3 and SrTiO3). In this article, the authors reviewed the features, proposed mechanisms and application of IBIEC to Si and other materials with the existing state of affairs.
A reaction with oxygen during oxygen exposure to Cerium metal surface under ultra high vacuum condition and depth profiling on formed Cerium oxide layer were investigated in term of chemical state analysis by Auger electron spectroscopy (AES) and by factor analysis. Principal component analysis (PCA) on Ce NON Auger spectra suggested that three physically meaningful components existed from the analyzed data in both cases. After the PCA, three spectra were extracted from the data and these showed significant peak shape changes in each spectrum which were corresponding to different chemical states. In addition, the profiles constructed by factor analysis showed the chemical state changes on the Cerium metal surface during oxidation or chemical depth distributions in the oxide layer.
Rechargeable lithium batteries are very attractive as a high-energy power source. This is due to the high voltage property of these batteries. Such high voltage is accomplished through the use of a strong oxidant and reductant. The result is the oxidative or reductive decomposition of electrolytes. In conventional batteries, these undesirable reactions have to be suppressed to obtain high reliability and safety. For this purpose, interfaces between electrolytes and cathode or anode materials should be controlled artificially. Especially, dynamic control is strongly needed because the discharge/charge cycle is repeated many times. In this report, some dynamic and artificial control methods for interfaces are introduced from the viewpoint of a surface chemistry in the development of rechargeable lithium batteries.
We have developed an easy-to-use electrostatic force microscope for operation in ultrahigh vacuum (UHV), based on the scanning Maxwell stress microscope (SMM), for application to surface science and nanoelectric devices. The SMM head is built on an UHV-flange with setting all the optical parts in the air side. This design makes operation of our UHV-SMM as convenient as operating an instrument in air. The stable oscillation at very small tip-sample separation without persistent adhesion under UHV opens up the possibility to improve the lateral resolution of the SMM.