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Structure,morphology and electrical resistance of W_(x)N thin film synthesized by HFCVD method with various N_(2) contents

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Rare Metals 2020年第12期39卷 1440-1448页

作者： Somayeh Asgary Mohammad Reza Hantehzadeh Mahmood Ghoranneviss Arash boochani s.asgary m.r.hantehzadehm.ghoranneviss*.1.boochaniplasmaphysics research centerscience and research branchislamic azad universitytehran 14665-678iran department of physics kermanshah branchislamic azaduniversitykermanshah ***iran

Tungsten nitride(W_(x)N)thin films with good crystalline structure,high quality and relatively low resistivity were deposited by hot filament chemical vapor deposition(HFCVD)technique at different mixtures of N2 and Ar *** data demonstrate that different N_(2) contents in gas mixture strongly affect microstructure,phase formation,texture morphology and resistivity of the W_(x)N *** to X-ray diffraction(XRD)patterns,the growth of tungsten nitride films promotes δ-WN phase for lower N_(2) contents in gas *** higher N_(2) contents,a phase transition is observed in the tungsten nitride *** hexagonal δ-WN and cubic β-W_(2)N phases coexist,and WN phase approximately disappears with N_(2) contents in the gas mixture *** electron microscope(SEM)images for deposited films at lower N_(2) contents in gas mixture indicate a definite dense columnar *** electrical resistivity results exhibit a significant drop for the W_(x)N thin films with N_(2) contents in the mixed gas *** changes in N_(2) content in gas mixture are found to be responsible for variation in the film resistivity ***,the deposited tungsten nitride thin film at higher N_(2) contents in gas mixture has noncolumnar microstructure and lower resistivity,which may be used as a superior diffusion barrier.

关键词： Tungsten nitride Thin film HFCVD Electrical resistivity Diffusion barriers

Elastic and optical properties of zinc-blende CrSb and its effective mass

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Rare Metals 2014年第5期33卷 615-621页

作者： Sahar Rezaee Arash boochani Masoud Majidiyan Atefeh Ghaderi Shahram Solaymani Mosayeb Naseri Department of Physics College of ScienceIslamic Azad University Physics Department Sabzevar Tarbiat Moallem University Young Researchers and Elite Club Islamic Azad University

The elastic, optical, and effective mass properties of CrSb in zinc-blende（ZB） phase were *** calculations were carried out using the full-potential linearized augmented plane wave plus local orbital according to the density functional theory. The results of elastic calculations by generalized gradient approximation and local density approximation approximations indicate that ZB CrSb is a ductile material and its Debye temperature is rather low. Band structure and density of state calculations introduce the ZB CrSb as a half-metal with spin polarization of100 %. In metal state, 16 th and 17 th bands cut off the Fermi level. Calculations study the effective mass, Fermi velocity,and Fermi surface at 16 th and 17 th bands. In continue,optical quantities such as dielectric function, energy loss function, and optical conductivity were investigated.

关键词： Half-metal CrSb Elastic properties Optical properties

Ti Impurity Effect on the Optical Coefficients in 2D Cu_2Si: A DFT Study

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Communications in Theoretical Physics 2018年第1期69卷 101-106页

作者： Bromand Nourozi Arash boochani Ahmad Abdolmaleki Elmira Sartpi Pezhman Darabi Sirvan Naderi Department of Physics Islamic Azad UniversityKermanshah Branch Department of Physics Lorestan University Young Researchers and Elite Club Kermanshah Branch Islamic Azad University

The electronic and optical properties of 2D Cu_2Si and Cu_2Si:Ti are investigated based on the density functional theory(DFT) using the FP-LAPW method and GGA approximation. The 2D Cu_2Si has metallic and non magnetic properties, whereas adding Ti impurity to its structure changes the electronic behavior to the half-metallic with 3.256μB magnetic moment. The optical transition is not occurred in the infrared and visible area for the 2D Cu_2Si in x-direction and by adding Ti atom, the real part of dielectric function in the x-direction, Re(ε(ω))_x is reached to a Dirac peak at this energy range. Moreover, the absorption gap tends to zero in x-direction of the 2D Cu_2Si:Ti.

关键词： 2D Cu2Si Ti impurity DFT optical property

Thermodynamic Stability, Half-Metallic and Optical Properties of Sc_(2)CoSi [001] Film:a DFT Study

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Communications in Theoretical Physics 2019年第4期71卷 455-462页

作者： Maliheh Amiri Hossein Akbari Bashir Nedaee-shakarab Arash boochani Amin Aminian Yousof Zangeneh Sirvan Naderi Department of Physics Kermanshah Branch Islamic Azad University Department of Physics Ardabil Branch Islamic Azad University Department of physics university of Guilan Young Researchers and Elite Club Kermanshah Branch Islamic Azad University

The electronic and optical characteristics of the Sc2 CoSi Heusler with L21 structure and also the surface effect on electronic and optical properties, and the ?lms thermodynamic stability of the [001] direction in four cases including:Sc-Sc, Sc-Co, Sc-Si and Co-Si terminations are studied using the ?rst principles calculations(FPLAPW) within the framework of the density functional theory(DFT). The band structure calculations represent the ferromagnetic halfmetallic properties with 100% spin polarization and 0.54 e V indirect gap in spin down for Sc2 CoSi bulk with optimized lattice parameters of 6.25 A?. The total magnetic moment obtained for this compound is-1.0 μB, which is in accordance with Slater-Pauling rule. The half-metallic(HM) behavior by 100% spin polarization at Fermi level is occurred in the Sc-Si termination with a 0.32 eV gap in down spin. The optical responses have been calculated for the bulk and ScSi termination by a red shift in these parameters and the metallic treatments have been increased. According to the thermodynamic phase diagrams, it is shown the Sc-Si and Sc-Sc terminations are more stable than other terminations.

关键词： half-metalicity DFT thermodynamic stability thin films Heusler alloy first-principles calculations

Calculation of Half-Metal, Debye and Curie Temperatures of Co_2 VAl Compound: First Principles Study

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Communications in Theoretical Physics 2015年第5期63卷 641-647页

作者： Arash boochani Heidar Khosravi Jabbar Khodadadi Shahram Solaymani Masoud Majidiyan Sarmazdeh Rohollah Taghavi Mendi Sayed Mohammad Elahi Department of Physics Kermanshah Branch Islamic Azad University Young Researchers and Elite club Kermanshah Branch Islamic Azad University Department of Physics Payame Noor University Department of Physics Mashhad Branch Islamic Azad University

By FP-LAPW calculations, the structural, elastic, Debye and Curie temperatures, electronic and magnetic properties of Co2 VAl are investigated. The results indicate that Ferromagnetic （FM） phase is more stable than Anti- Ferromagnetic （AFM） and Non-magnetic （NM） ones. In addition, C11-C12 〉 0, C44 〉 0, and B 〉 0 so Co2 VAl is an elastically stable material with high Debye temperature. Also, the BIG ratio exhibits a ductility behavior. The relatively high Curie temperature provides it as a favorable material for spintronic application. It＇s electronic and magnetic properties are studied by GGA ＋U approach leading to a 100% spin polarization at Fermi level.

关键词： exchange energy Debye temperature Curie temperature Co2VAl GGA+U

Physical Properties of CrSb/InP(001): Effect of Interface in Half-Metallic

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World Journal of Nano Science and Engineering 2013年第3期3卷 79-86页

作者： Arash boochani Shahram Solymani Sahar Rezaee Negin Beryani Nezafat Sara Fakhrai Tadayon Amin Aminian Department of Physics Faculty of Science University of Guilan Guilan Iran Department of Physics Kermanshah Branch Islamic Azad University Kermanshah Iran Department of Physics Kermanshah Science and Research Branch Kermanshah Iran Young Researchers and Elite Club Kermanshah Branch Islamic Azad University Kermanshah Iran

In this study, density functional theory in improved flat waves’ framework has been used. First of all, characterization, elastic and half-metallic properties of the CrSb-ZB compound at (GGA & LDA) and GGA + U approximation are calculated. The elastic calculations indicate that the CrSb-ZB is a ductile material. However, the calculation of Deby temperature indicates that the CrSb-ZB is meta-stable. The half-metallicity character is also preserved at CrSb/InP (001) interface by GGA + U. The conduction band minimum (CBM) of CrSb in the minority spin case lies about 1.26 eV above that of GaSb, suggesting that the major spin can be injected into GaSb without being flipped to the conduction bands of the minor spin.

关键词： Spintronic Interface Crsb-Inp Density Functional Theory GGA + U