材料期刊网

RANGE PARAMETERS IN METALS AND ALLOYS

WANG Dening , WANG Weiyuan Ion Implantation Lab. , Shanghai Institute of Metallurgy , Academia Sinica , Shanghai , China Associate Professor , Laboratory No.6 , Shanghai Institute of Metallurgy , Academia Sinica , Shanghai 200050 , China

金属学报(英文版)

The formulae for calculating the electronic stopping power.for heavy ion implanting into metal are derived by using Wigner-Sietz radius r_s,equivalent charge,Fermi velocity and Ziegler's values of hydrogen electronic stopping power.Meanwhile the.formulae of electronic stopping power S_e(E)for alloys with boride or CsCl structure are also proposed.The calculated results are found as follows:these formulae are suitable only for mono-or bi-borides,but not for borides with more complex structure such as Cr_5B_3 or W_2B_5;the coefficient γ,of S_e(E)for al- loys with CsCI structure deviating from Bragg's S_e(E)is directly proportional to charge trans- fer in alloy.This means the larger the charge transfer is,the more stronger the metallic bond is.Hence the S_e(E)created by metallic bond in alloys will increase; there is a tendency for it to increase with increasing separation of two components in alloy on either side of Cr group at same periods,when the two components are in different periods,the tendency is more larger.

关键词: metal , null , null , null

ION HEATING PROCESS DURING PLASMA IMMERSION ION IMPLANTATION

X.B. Tian , X.F. Wang , A.G. Liu , L.P. Wang , S. Y. Wang , B. Y. Tang and P. K. Chu 1)Advanced Welding Production & Technology National Key Laboratory , Harbin Institute of Technology , Harbin 150001 , China 2)Department of Physics & Materials Science , City University of Hong Kong , China

金属学报(英文版)

The research on plasma immersion ion implantation has been conducted for a little over ten years. Much is needed to investigate including processing technlogy, plasma sheath dynamics, interaction of plasma and surface, etc. Of the processing methods elavated temperature technique is usually used in PIII to produce a thick modified layer by means of the thermal diffusion. Meanwhile plasma ion heating is more recently developed by Ronghua Wei et al[1]. Therefore the temeperature is a critical parameter in plasma ion processing. In this paper we present the theoretical model and analysize the effect of imlantation voltage, plasma density, ion mass,etc on the temperature rise.

关键词: plasma immersion ion implantation , null , null

Synthesis of molybdenum silicide by both ion implantation and ion beam assisted deposition

Applied Surface Science

Two groups of Mo/Si films were deposited on surface of Si( 1 0 0) crystal. The first group of the samples was prepared by both ion beam assisted deposition (IBAD) and metal vapor vacuum arc (MEVVA) ion implantation technologies under temperatures from 200 to 400 degrees C. The deposited species of IBAD were Mo and Si, and different sputtering Ar ion densities were selected. The mixed Mo/Si films were implanted by Mo ion with energy of 94 keV, and fluence of Mo ion was 5 x 10(16) ions/cm(2). The second group of the samples was prepared only by IBAD under the same test temperature range. The Mo/ Si samples were analyzed by X-ray diffraction (XRD), atomic force microscopy (AFM), scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), sheet resistance, nanohardness, and modulus of the Mo/ Si films were also measured. For the Mo/ Si films implanted with Mo ion, XRD results indicate that phase of the Mo/Si films prepared at 400 and 300 degrees C was pure MoSi2. Sheet resistance of the Mo/ Si films implanted with Mo ion was less than that of the Mo/Si films prepared without ion implantation. Nanohardness and modulus of the Mo/ Si films were obviously affected by test parameters. (C) 2007 Elsevier B. V. All rights reserved.

关键词: molybdenum silicide;MEVVA;IBAD;nanohardness;mechanical-properties;adhesion strength;internal-stress;films;tin;nanoindentation;substrate;coatings;hardness;layer

C and Si ion implantation and the origins of yellow luminescence in GaN

Applied Physics a-Materials Science & Processing

We have studied the influence of C and Si ion implantation with different implantation doses on yellow luminescence (YL) from GaN. Three kinds of GaN samples were used. In their as-grown states, #1 samples had strong YL, #2 samples had no YL, while #3 samples had weak YL. Our experimental results show that: (i) after annealing at 950 degreesC, the YL intensity for Si ion implanted #1 sample decreased with increasing implantation dose, while that for C ion implanted #1 sample exhibited a reverse rule; (ii) for #2 samples, C ion implantation produced much stronger YL than Si ion implantation did after annealing at 950 degreesC; (iii) the YL intensity sequence for Si ion implanted and 950 degreesC annealed #1, #2, and #3 samples was consistent with that for the unimplanted #1, #2, and #3 samples. However, the YL intensity sequence for the C ion implanted and 950 degreesC annealed #1, #2, and #3 samples reversed with that for the unimplanted ones. In order to explain all these phenomena, we suggested a physical model which claims that the deep C center is another important origin of YL in GaN, and during C ion implantation, the C ion prefers to combine with a V-Ga to form a C-Ga.

关键词: detected magnetic-resonance;vapor-phase epitaxy;undoped gan;photoluminescence;vacancies;nitrides

Morphology Control and Optical Absorption Properties of Ag Nanoparticles by Ion Implantation

G.X. Cai

材料科学技术（英）

Ion implantation is a powerful method for fabricating nanoparticles in dielectric. For the actual application of nanoparticle composites, a careful control of nanoparticles has to be achieved. In this letter, the size, distribution and morphology of Ag nanoparticles are controlled by controlling the ion current density, ion implantation sequence and ion irradiation dose. Single layer Ag nanoparticles are formed by Ag⁺ ion implantation at current density of 2.5 μA/cm². By Ag and Cu ions sequential implantation, the size of single layer Ag nanoparticles increases. While, by Cu and Ag ions sequential implantation, uniform Ag nanoparticles with wide distribution are formed. The morphology of Ag nanoparticles changes to hollow and sandwiched nanoparticles by Cu⁺ ion irradiation to doses of 3×10¹⁶ and 5×10¹⁶ ions/cm². The optical absorption properties of Ag nanoparticles are also tailored by these ways.

关键词: Nanoparticles , null , null

Capacitance of High-Voltage Coaxial Cable in Plasma Immersion Ion Implantation

X.B. Tian , L.P. Wang , D. T.K.Kwok , B. Y Tang , P.K.Chu

材料科学技术（英）

Plasma immersion ion implantation (PIII) is an excellent technique for the surf see modification of complex-shaped components. Owing to pulsed operation mode of the high voltage and large slew rate, the capacitance on the high-voltage coaxial cable can be detrimental to the process and cannot be ignored. In fact, a significant portion of the rise-time/fall-time of the implantation voltage pulse and big initial current can be attributed to the coaxial cable.

关键词:

Beryllium Surface Modified by B Ion Implantation

HU Renyuan YANG Yushi Institute of Low Energy Physics , Beijing Normal University , China. Beijing Research Institute of Materials and Technology , China.

材料科学技术（英）

Beryllium is implanted with 100 keV, 2×10~(17) B/cm~2 and post-implanted sample is annealed at 650℃ for 1 h.Hardness measurement indicates that the hardness increases with implantation and can further be modified by post-implantation heat treatment. Profile measurement shows that implantation causes contamination on the surface of beryllium. During annealing boron diffuses out of beryllium and carbon on surface diffuses into beryllium. Beryllium surface is modified by composition change and carbide formation.

关键词: ion implantation , null , null

Effect of Co Ion Implantation on GMR of [NiFeCo(10 nm)/Ag(10 nm)]×20 Multilayer Film

Yuding HE , Shejun HU , Jian LI , Guangrong XIE

材料科学技术（英）

The composition, phase structure and microstructure of the discontinuous multilayer film [NiFeCo(10 nm)/ Ag(10 nm)]×20 were investigated after Co ion implantation and annealing at 280, 320, 360 and 400℃, respectively. GMR (giant magnetoresistance) ratio of the film with/without Co ion implantation was measured. The results showed that Co ion implantation decreased the granule size of the annealed multilayer film, and increased Hc value and GMR ratio of the multilayer film. After annealing at 360℃, the multilayer film [NiFeCo(10 nm)/Ag(10 nm)]×20 with/without Co ion implantation both exhibited the highest GMR ratio of 12.4%/11% under 79.6 kA/m of applied saturation magnetic field.

关键词: Co ion implantation , null , null

Optical and magnetic properties of Ni/NiO nanopartilces in YSZ by metal ion implantation and post-implantation annealing

Physica B-Condensed Matter

Sixty four keV Ni+-ion implantation in yttria-stabilized zirconia (YSZ) was conducted at the room temperature up to a fluence of 1 X 10(17) ion/cm(2). The as-implanted crystals were annealed isochronally at temperatures up to 900 degrees C in ambient atmosphere. Optical absorption spectroscopy.. X-ray photoelectron spectroscopy (XPS), transmission electron microscopy (TEM), and a superconducting quantum interference device (SQUID) magnetometer have been utilized to characterize the samples. XPS results showed that the charge state of Ni was mainly Ni-0 in as-implanted and Ni2+ in annealed samples. However, TEM analysis did not reveal any obvious metallic Ni nanoparticles or amorphization of YSZ after ion implantation. After annealing, NiO nanoparticles with size ranging from 4 to 12 nm were observed. The larger nanoparticles distributed near the surface of the YSZ. High-resolution TEM image clearly demonstrated the crystallinity of the nanoparticles. Optical absorption spectroscopy did not clearly detect the absorption bands of Ni or NiO nanoparticles. Magnetic measurement indicated that the coercive force of residual Ni nanoparticles was similar to 270 Oe at 10 K in annealed crystals. (c) 2005 Elsevier B.V. All rights reserved.

关键词: ion implantation;nanoparticles;annealing;optical;magnetic;yttria-stabilized zirconia;single-crystals;microstructure;size

Effects of Hydrogen Ion Implantation on TiCC Coating of Stainless Steel

ZHANG Ruiqian , LIU Yaoguang , HUANG Ningkang

钢铁研究学报(英文版)

Titanium carbide coatings are widely used as various wearresistant material. The hydrogen erosion resistance of TiCC films and the effect of hydrogen participation on TiCC films were studied. Seventyfive percent TiCC films are prepared on stainless steel surface by using ion mixing, where TiCC films are deposited by rf magnetron sputtering followed by argon ion bombardment. The samples are then submitted to hydrogen ion implantation at 12×10-3 Pa. Characterization for the 75% TiCC films was done with SIMS, XRD, AES, and XPS. Secondary ion mass spectroscopy (SIMS) was used to analyze hydrogen concentration variation with depth, XRay diffraction (XRD) was used to identify the phases, and Auger electron spectra (AES) as well as Xray photoelectron spectra (XPS) were used to check the effects of hydrogen on shifts of chemical bonding states of C and Ti in the TiCC films. It is found that TiCC films on stainless steel surface can prevent hydrogen from entering stainless steel.

关键词: hydrogen resistance;carbide;coating;ion implantation