Effect of Co,Pd and Pt ultra-thin films on the Ni-silicide formation: investigating the sandwich configuration

The effect of Co, Pd and Pt ultrathin films on the kinetics of the formation of Ni-silicide by reactive diffusion is investigated. 50 nm Ni/1 nm X/ 50 nm Ni (X?=?Co, Pd, Pt) deposited on Si(100) substrates are studied using in-situ and ex-situ measurements by X-ray diffraction (XRD). The presence of Co, Pd or Pt thin films in between the Ni layers delays the formation of the metal rich phase compared to the pure Ni/Si system and thus these films act as diffusion barriers. A simultaneous silicide formation (δ-Ni₂Si and NiSi phases) different from the classic sequential formation is found during the consumption of the top Ni layer for which Ni has to diffuse through the barrier. A model for the simultaneous growth in the presence of a barrier is developed, and simulation of the kinetics measured by XRD is used to determine the permeability of the different barriers. Atom probe tomography (APT) of the Ni/Pd/Ni system shows that the Pd layer is located between the Ni top layer and δ-Ni₂Si during the silicide growth, in accordance with a silicide formation controlled by Ni diffusion through the Pd layer. The effect of the barrier on the silicide formation and properties is discussed.

     

A novel visible spectrum images-based pedestrian detection and tracking system for surveillance in non-controlled environments

Multimedia Tools and Applications - For many vision applications, robust detection and tracking of pedestrians in image sequences are essential. In this paper, a hybrid system for pedestrian...     

Fluorescent Polyimide Films Produced with Diatomite and Mesoporous Silica as Promising High-Tech Material

Journal of Inorganic and Organometallic Polymers and Materials - Due to their excellent properties, polymides (PIs) result promising as high-performance materials in different technological fields....     

Influence of silicon carbide on structural,optical and magnetic properties of Wollastonite/Fe2O3 nanocomposites

The influence of adding 10, 20 and 30% molar ratio of silicon carbide (SiC) separately to a composite of wollastonite (W) with a fixed content of 10%Fe₂O₃ prepared by wet precipitation method was studied. The crystal structure of the annealed composite powders was inspected by X-ray diffraction (XRD); revealing multi-phase structure. The highest estimated crystallite size investigated by Scherrer equation of W, SiC, WFe:SiC₁₀, WFe:SiC₂₀ and WFe:SiC₃₀ were 53.89, 54.6, 56.3, 48.5 and 54.6 nm respectively; demonstrating the formation of nanocomposites. Particles shape, size and crystallinity of the samples were studied using high resolution transmission electron microscope (HR-TEM). The band gap E_g values of the nanocomposites increased with SiC content having an intermediate value that lies between that of γ-Fe₂O₃ (maghemite) and SiC. Ferromagnetic and paramagnetic contributions were observed in the magnetic hysteresis loops for the composites. This study highlighted that the coercive field (H_ci) of the composites improved with increasing the SiC content. The innovative wollastonite/Fe₂O₃/SiC with amended magnetic properties elicited attention due to their promising application in bone filler and industrial purposes.     

Strain mediated enhancement in magnetoelectric properties of sonochemically synthesized piezoelectric and piezomagnetic composites

Materials with magneto-electric (ME) properties are of great importance because of their demand in electronic industries. Three dimensional nano-particles of the ME-composites having the general formula (1-x)CoCr_0.3Fe_1.7O₄(CCFO)+(x)BaTiO₃(BTO) (x = 0.0, 0.2, 0.4, 0.6, 0.8 and 1.0) were obtained by comprising the piezoelectric-BTO and piezomagnetic-CCFO phases. The individual phases of CCFO and BTO were synthesized separately by ultrasonic irradiation assisted sonochemical and sol-gel routs. X-ray diffraction patterns (XRD) confirmed the well-crystalline nature of both the phases. BTO and CCFO phases were under tensile strain as confirmed by the variation in lattice constants with varying proportion of BTO and CCFO. An energy-dispersive X-ray spectroscopy spectrum confirmed the phase purity of the samples and stoichiometric concentration of elements. Magnetic properties were investigated by M ? H loop measurements and dielectric properties by using RF impedance analyzer. Dielectric constant increased with the increasing percentage of BTO. The maximum value of ME coefficient (24.7 mV/cm?Oe) is observed for the 60%CCFO+40%BTO sample. The obtained results were discussed in the light of grain size, strain and the basic properties of the individual phases. The prepared materials can be applicable in electronic devices where high magneto-electric coefficient is desirable.     

Embedding in medical images: an efficient scheme for authentication and tamper localization

Multimedia Tools and Applications - In e-healthcare applications integrity of the received information is of prime importance for ensuring the accurate diagnosis. The integrity of electronic...     

A comparative study on the effect of loading speed and surface scratches on the flexural strength of aluminosilicate glass: Annealed vs. chemically strengthened

Quasi-static and dynamic three-point-bending experiments were conducted on both annealed and chemically strengthened aluminosilicate glass scratched by different normal loads. Scratched areas were observed by optical microscope and atomic force microscope. Chemically strengthened glass shows better resistance to surface scratch. These dynamic experiments were carried out using a modified Split Hopkinson Pressure Bar (SHPB) device and a pulse-shaping technique was used to keep constant loading speed to the specimens. In tests, high-speed photography was also used to observe the failure process of the specimens. The test results showed that the flexural strength of aluminosilicate glass (AG) strongly depends on the applied loading speed. Compared with its annealed counterpart, the chemically strengthened glass (CSG) showed higher flexural strength to both static and dynamic loadings. Moreover, the three-point bending experiments were conducted on scratched AG and CSG specimens and decrease of 20–40% in flexural strength was observed. The fractography analysis showed that in dynamic loading conditions the fracture surface was not smooth and has more secondary cracks as compared to static loading.