This study deals with an experimental investigation of structural and magnetic properties of LaNi5 and MmNi4.7Al0.3 (Mm consists of 66.6 wt% Ce and 33.3 wt% La) hydrogen storage alloys. LaNi5 and MmNi4.7Al0.3 alloys were prepared by vacuum induction melting method and then hydrogenated under 50 bar hydrogen gas pressure. The structure of the samples, before and after hydrogenation, was probed by X-ray diffraction (XRD) analysis which showed that all the samples have a single phase hexagonal crystal structure (CaCu5-type). Then X-ray fluorescence (XRF) measurement was used to investigate the chemical compound of the as-prepared samples. The study of the magnetic properties of samples indicated that the as-prepared alloys are weakly ferromagnetic or paramagnetic, while the hydrogenation process causes ferromagnetic behavior of samples to intensify. Honda-Arrott plot analysis exhibited that substitution of Al for Ni and Ce for La in the as-prepared samples reduces the magnetic susceptibility from 4.8 × 10−6 to 3.06 × 10−6 emu/gOe. Magnetic anisotropy of the hydrogenated samples in a high magnetic field was studied using the law of approach to saturation. The results indicated that the magnetic anisotropy and anisotropy field increase by the replacement of Ni and La with Al and Ce respectively.

s of Papers in English Investigation of Al and PET flexible substrate effects on structural and optical properties of the absorber layer CIS M.H. Amerioun M.E. Ghazi M. Izadifard B. Bahramian Received: 2015.2.5 Accepted: 2015.11.24 Abstract Due to the proper direct ban gap and high absorption coefficient of CuInS (CIS) absorber layer, this layer devoted much attention to itself. By using flexible substrates in solar cell fabrication causes to increase the benefit of CIS usage. The solar cell based on CIS, due to their high conversion efficiency, their low cost potential and the many application possibilities are very attractive. They can be grown on metal or polymer substrate with a variety of deposition methods. The conversion efficiency depends on the choice of the substrates and of the processing technology. In this research, we prepare and characterize structural and optical properties of CIS absorber layers on Al and polymer as tow flexible substrate. As the results, by changing the substrate from Aluminum to Polymer, the crystalline size and strain of CIS layers were changed. These changes are probably related to coefficient of thermal expansion of Aluminum, polymer substrates and CIS layer. In addition, Aluminum substrate can decrease resistivity (increase conductivity) of CIS absorber layer.Due to the proper direct ban gap and high absorption coefficient of CuInS (CIS) absorber layer, this layer devoted much attention to itself. By using flexible substrates in solar cell fabrication causes to increase the benefit of CIS usage. The solar cell based on CIS, due to their high conversion efficiency, their low cost potential and the many application possibilities are very attractive. They can be grown on metal or polymer substrate with a variety of deposition methods. The conversion efficiency depends on the choice of the substrates and of the processing technology. In this research, we prepare and characterize structural and optical properties of CIS absorber layers on Al and polymer as tow flexible substrate. As the results, by changing the substrate from Aluminum to Polymer, the crystalline size and strain of CIS layers were changed. These changes are probably related to coefficient of thermal expansion of Aluminum, polymer substrates and CIS layer. In addition, Aluminum substrate can decrease resistivity (increase conductivity) of CIS absorber layer.

In this work, first the CuInS2 (CIS2) layers are deposited on Aluminum and polyethylene terephthalate (PET) as flexible substrates, and on glass and soda lime glass (SLG) as rigid substrates by the sol-gel method. Then the samples are analyzed by x-ray diffractomery (XRD) and atomic force microscope (AFM) to investigate the crystal structures and surface roughness of the samples. The I-V curve measurements and Seebeck effect setup are used to measure the electrical properties of the samples. The XRD data obtained for the CIS2 layers show that all the prepared samples have a single phase with a preferred orientation that is substrate-dependent. The samples grown on the rigid substrates had higher crystallite sizes. The results obtained for the optical measurements indicate the dependence of the band gap energy on the substrate type. The measured Seebeck coefficient showed that the carriers were of p-type in all the samples. According to the AFM images, the surface roughness also varied in the CIS2 layers with different substrates. In this regard, the type of substrate could be an important parameter for the final performance of the fabricated CIS2 cells.

CuInSe2 , CuInS2 ( CIS2 and CuInGaS2 alloys and their compounds with band gaps between 1.05 and 1.7eV are absorbance materials based on chalcopyrite, in which, because of their suitable direct band gap, high absorbance coefficient and short carrier diffusion are used as absorbance layers in solar cells. In this work, the effects of decrease in p H and thickness variation on characteristics of the CIS2 absorber layers, grown by spin coating on glass substrates, are investigated. Furthermore by using thiourea as a sulphur source in solvent, the sulfurization of layers was done easier than other sulfurization methods. Due to the difficulty in dissolving thiourea in the considered solvent that leads to a fast deposition during the dissolving process, precise conditions are employed in order to prepare the solution. In fact, this procedure can facilitate the sulfurization process of CuIn layers. The results obtained from this investigation indicate reductions in absorbance and band gap in the visible region of the spectrum as a result of decrease in p H. Finally, conductivity of layers is studied by the current vs. voltage curve that represents reduction of electrical resistance with decrease and increase in p H and thickness, respectively.

Due to producing both metallic and semiconducting carbon nanotubes simultaneously during growth procedure, it is probably needed to separate them after synthesize. In this article a novel and efficient method for separating metallic single-walled carbon nanotubes from semiconducting is proposed. This method is based on magnetic properties of carbon nanotubes and takes advantages of an electromagnet in order to apply magnetic field on carbon nanotubes. In this work, carbon nanotubes are utilized in the solid phase. Results are discussed by analyzing field emission scanning electron microscopy images, X-ray diffraction, and Raman spectroscopy diagrams and also by measuring the resistivity of samples.

In this work, CuInS2/multiwalled carbon nanotube (MWCNT) layers are fabricated by the sol–gel spin-coating method. We introduce two forms of MWCNTs into a CIS2 solution, washed functional multiwalled carbon nanotubes (W-FMWCNTs) and unwashed-functional multiwalled carbon nanotubes (UW-FMWCNTs), in order to investigate the effects of MWCNTs and an acidic environment on the physical properties of the CIS2 absorber layers. The structure and morphology of the samples are investigated by X-ray diffraction (XRD) and field emission scanning electron microscopy (FESEM), respectively. The XRD study shows that all samples crystallize in a tetragonal structure. The results obtained from the optical, thermo-electric, and electrical measurements indicate that the two groups of CIS2 layers prepared using W- and UW-FMWCNTs show the opposite behaviors. The Seebeck coefficient (SC) measurements indicate possible formation of a p–n junction.