I P Jain
Articles written in Bulletin of Materials Science
Volume 27 Issue 4 August 2004 pp 393-394 Surfaces and Interfaces
The present work deals with the mixing of metal and silicon by swift heavy ions in high-energy range. Threshold value for the defect creation in metal Fe calculated was found to be ∼ 40 keV/nm. A thin film of Fe (10 nm) was deposited on Si (100) at a pressure of 4 × 10-8 Torr and was irradiated with 95 MeV Au ions. Irradiation was done at RT, to a dose of 1013 ions/cm2 and 1 pna current. The electronic energy loss was found to be 29.23 keV/nm for 95 MeV Au ions in Fe using TRIM calculation. Compositional analysis of samples was done by Rutherford backscattering spectroscopy. Reflectivity studies were carried out on the pre-annealed and post-annealed samples to study irradiation effects. Grazing incidence X-ray diffraction was done to study the interface. It was observed that ion beam mixing reactions at RT lead to mixing as a result of high electronic excitations.
Volume 29 Issue 1 February 2006 pp 67-72 Alloys
The structural, electrical and thermodynamic properties of a La–Ni–Si [La = 28.9%, Ni = 67.5%, Si = 3.6%] alloy have been investigated. Powder XRD results show that the lattice constants and unit cell volume of the alloy increase after hydrogen storage. It was also found that the resistance of the alloy increased with dissolved hydrogen concentration. Hydrogen absorption pressure composition isotherms have also been investigated which show the presence of two single 𝛼 and 𝛽 regions and one mixed (𝛼 + 𝛽) phase. The thermodynamic parameters viz. the relative partial molar enthalpy (𝛥 𝐻) and relative partial molar entropy (𝛥 𝑆) of dissolved hydrogen, are found to be in the range 8–18 kJ (mol H)-1 and 25–63 JK-1 (mol H)-1. From the dependence of 𝛥 𝐻 on the hydrogen concentration, 𝑋, the different phases [𝛼, 𝛼+ 𝛽, 𝛽] and phase boundaries of the alloy-𝐻 system are identified. Thermal conductivity and diffusivity of La–Ni–Si and its hydride have been measured at room temperature by using TPS technique. Thermal conductivity was found to decrease due to absorbed hydrogen in the alloy.
Volume 29 Issue 2 April 2006 pp 187-191 Electrical Properties
Synthesis of swift heavy ion induced metal silicide is a new advancement in materials science research. We have investigated the mixing at Co/Si interface by swift heavy ion beam induced irradiation in the electronic stopping power regime. Irradiations were undertaken at room temperature using 120 MeV Au ions at the Co/Si interface for investigation of ion beam mixing at various doses: 8 × 1012, 5 × 1013 and 1 × 1014 cm-2. Formation of different phases of cobalt silicide is identified by the grazing incidence X-ray diffraction (GIXRD) technique, which shows enhancement of intermixing and silicide formation as a result of irradiation. 𝐼–𝑉 characteristics at Co/Si interface were undertaken to understand the irradiation effect on conduction mechanism at the interface.
Volume 29 Issue 6 November 2006 pp 647-651
The interaction of Co (30 nm) thin films on Si (100) substrate in UHV using solid state mixing technique has been studied. Cobalt was deposited on silicon substrate using electron beam evaporation at a vacuum of 4 × 10-8 Torr having a deposition rate of about 0.1 Å/s. Reactivity at Co/Si interface is important for the understanding of silicide formation in thin film system. In the present paper, cobalt silicide films were characterized by atomic force microscopy (AFM) and secondary ion mass spectroscopy (SIMS) in terms of the surface and interface morphologies and depth profile, respectively. The roughness of the samples was found to increase up to temperature, 300°C and then decreased with further rise in temperature, which was due to the formation of crystalline CoSi2 phase. The effect of mixing on magnetic properties such as coercivity, remanence etc at interface has been studied using magneto optic Kerr effect (MOKE) techniques at different temperatures. The value of coercivity of pristine sample and 300°C annealed sample was found to be 66 Oe and 40 Oe, respectively, while at high temperature i.e. 748°C, the hysteresis disappears which indicates the formation of CoSi2 compound.
Volume 30 Issue 2 April 2007 pp 153-156 Thin Films
The present work deals with the mixing of iron and silicon by swift heavy ions in high-energy range. The thin film was deposited on a 𝑛-Si (111) substrate at 10-6 torr and at room temperature. Irradiations were undertaken at room temperature using 120 MeV Au+9 ions at the Fe/Si interface to investigate ion beam mixing at various doses: 5 × 1012 and 5 × 1013 ions/cm2. Formation of different phases of iron silicide has been investigated by X-ray diffraction (XRD) technique, which shows enhancement of intermixing and silicide formation as a result of irradiation. 𝐼–𝑉 measurements for both pristine and irradiated samples have been carried out at room temperature, series resistance and barrier heights for both as deposited and irradiated samples were extracted. The barrier height was found to vary from 0.73–0.54 eV. The series resistance varied from 102.04–38.61 k𝛺.
Volume 42 | Issue 6
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