T (+98) 23 352 20220
Email: international@du.ac.ir
Damghan University
University Blvd, Damghan, IR
Mahdi Ardyanian
Assistant Professor of Condensed Matter Physics
TEL: +98-23-3522-0090
Biography
Dr. Ardyanian was born in Tehran, Iran. He received undergraduate degrees in applied physics (Solid State Physics) from Ferdowsi University, Mashhad, Iran (1993) and in Solid State Physics from Nancy University, France (2004). He earned a Ph.D. in Applied Condensed Matther Physics from Nancy University, France, (2007). He then held faculty position at the Damghan University, Semnan, Iran.
His Administrative portfolio includes vice dean of school of physics. He is currently Head of Solid State Department and assistant professor of condensed matter physics in Damghan university.
His research area lies in Synthesize and Characterization of Transparent Conductive Oxide Specially Zinc-Oxide nano-structures and nano-composites; and Zeolites.
Selected Publications
DOI: 10.1007/s10854-018-8701-4
Undoped and Cobalt (Co) doped zinc oxide (ZnO & CZx) nanoparticles were synthesized by Solvothermal method. The samples were studied by X-Ray Diffraction (XRD), Energy Dispersive X-ray Spectroscopy (EDS), Inductively Coupled Plasma Atomic Emission Spectroscopy (ICP-AES), UV–Vis spectroscopy and Scanning and Transmission Electron Microscopy (SEM & TEM). Moreover the gas sensing properties of the nanoparticles for methane gas took place. Purity of the samples and Co concentration was investigated by EDS and ICP spectroscopy respectively. XRD results described the hexagonal wurtzite structure for all the samples in which crystallinity and the crystallites size decreased with increase of Co doping level. Using UV–Vis spectroscopy the band gap energy was evaluated and redshift of band gap energy was observed by increasing of Co concentration. SEM images demonstrated that nanoparticles were agglomerated with increase of Co doping level. TEM images revealed the nanoparticles size in the range 11–44 nm. Methane sensing properties was enhanced after Co doping of the ZnO nanoparticles for Co concentration up to 4%. © 2018, Springer Science+Business Media, LLC, part of Springer Nature.
INDEX KEYWORDS: Atomic emission spectroscopy; Chemical detection; Energy dispersive spectroscopy; Energy gap; Gas detectors; Gas sensing electrodes; High resolution transmission electron microscopy; II-VI semiconductors; Inductively coupled plasma; Methane; Nanoparticles; Scanning electron microscopy; Synthesis (chemical); Transmission electron microscopy; X ray diffraction; Zinc oxide; Zinc sulfide; ZnO nanoparticles, Energy dispersive X ray spectroscopy; Gas sensing properties; Hexagonal wurtzite structure; Inductively coupled plasma atomic emission spectroscopy; Methane-gas sensing; Nanoparticles sizes; Scanning and transmission electron microscopy; Solvothermal method, Cobalt compounds
PUBLISHER: Springer New York LLC
DOI: 10.1007/s10854-017-8375-3
Zinc oxide (ZnO) and Titanium dioxide (TiO2) nano-particles were synthesized by sol–gel method. Next, (ZnO/TiO2) mono, double and multilayers were deposited by spin-coating technique on glass substrates. Structure, chemical bonds, optical properties, nano-particles size, surface morphology and multilayers structure were studied using X-ray diffraction (XRD) technique, Fourier Transform Infrared and UV-Vis-NIR spectroscopy, Transmission Electron Microscopy and Field Emission Scanning Electron Microscopy (FESEM), respectively. XRD results described the Wurtzite crystalline phase for ZnO and Anatase phase for TiO2 layers. Moreover based on Scherer equation, the TiO2 and ZnO nano-crystallites sizes were estimated about 11 and 25 nm respectively. XRD results also described increase of the layers crystallinity with increase of the layers number. Optical studies described despite of band-gap widening, transparency decreased with increase of layers number. This effect was attributed to the thin films thickness. TEM images described that the TiO2 nano-particles were smaller than ZnO one while more coalesced. FESEM images revealed that the multilayers contained of a flat and homogenous surface. © 2017, Springer Science+Business Media, LLC, part of Springer Nature.
INDEX KEYWORDS: Bond strength (chemical); Coatings; Electron emission; Electron microscopy; Energy gap; Field emission microscopes; Film preparation; High resolution transmission electron microscopy; Multilayers; Nanoparticles; Near infrared spectroscopy; Optical emission spectroscopy; Optical multilayers; Optical properties; Scanning electron microscopy; Sols; Spin glass; Substrates; Synthesis (chemical); Titanium dioxide; Titanium oxides; Transmission electron microscopy; X ray diffraction; Zinc compounds; Zinc oxide; Zinc sulfide, Fabrication and characterizations; Field emission scanning electron microscopy; Fourier transform infra reds; Spin-coating method; Thin films-thickness; TiO2 nano-particles; Titanium dioxides (TiO2); UV-vis-NIR spectroscopy, Titanium compounds
PUBLISHER: Springer New York LLC
DOI: 10.1007/s10854-017-7293-8
Nanoparticles of porous MoS2 have been synthesized by polymerizing-complexing sol–gel process using MoO3 powder in two precursors: (A) ammonia and (B) ammonium persulfate [(NH4)2S2O8]. The citric acid as complexing and ethylene glycol as polymerization agents were used. The structural properties of the prepared molybdenum disulfide nano-particles annealed at different temperatures of 200, 300, 400 and 750 °C in sulfur atmosphere have been characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM) and field emission scanning electron microscopy (FE-SEM) analyses. X-ray diffraction analysis showed the formation of MoS2 single-phase with hexagonal structure at annealing temperature of 750 °C in B precursor. The SEM images of MoS2 nanoparticles synthesized with ammonia (A) have shown a Rosette-like growth and also, MoS2 nanoparticles synthesized with (NH4)2S2O8 (B) had particle-cluster type growth with porous case. The values of band gap were obtained in the range of 3.96–2.95 and 3.11–2.02 eV from solutions consist of ammonia and (NH4)2S2O8, respectively. © 2017, Springer Science+Business Media, LLC.
INDEX KEYWORDS: Ammonia; Ammonium persulfate; Electron microscopy; Enamels; Energy gap; Ethylene; Ethylene glycol; Field emission microscopes; High resolution transmission electron microscopy; Molybdenum compounds; Molybdenum oxide; Nanoparticles; Scanning electron microscopy; Sols; Transmission electron microscopy; X ray diffraction analysis, Annealing temperatures; Chalcogenide semiconductors; Field emission scanning electron microscopy; Hexagonal structures; Molybdenum disulfide; Molybdenum sulfide; Porous nanoparticles; Synthesis and characterizations, Synthesis (chemical)
PUBLISHER: Springer New York LLC
DOI: 10.1007/s00339-016-0719-y
In this research, molybdenum disulfide (MoS2) nanoparticles were prepared by chemical reduction method using MoO3 and thiourea as a precursor. The physical properties of the synthesized MoO2–MoS2 nanoparticles annealed at different temperatures of 200, 300, 750 °C have been investigated, before and after exposure to sulfur vapor. The nanostructure of nanoparticles has been characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), transmission electron microscopy (TEM), field emission scanning electron microscopy (FE-SEM) analyses and UV–Vis spectrophotometer. The X-ray diffraction analysis showed the formation of MoS2 single phase at annealing temperature of 750 °C in the presence of sulfur vapor. The Raman spectrum of the nanoparticles revealed that the formation of MoS2 at 750 °C after annealing in sulfur vapor. The values of band gap were obtained in the range of 3.64–3.17 eV and 3.47–1.95 eV for MoS2 nanoparticles before and after exposure to sulfur vapor, respectively. According to SEM images, the grain size decreases with increasing annealing temperature up to 750 °C. Also, nanoplate–nanoparticles of MoS2 are formed at annealing temperature of 200–750 °C. The TEM images of MoS2 nanoparticles at Ta = 750 °C confirm that the nanoparticles have a homogeneous distribution with a hexagonal structure. The FTIR spectra of the MoS2 nanoparticles showed the peaks at about 467 cm−1 belong to the characteristic bands of Mo–S. © 2016, Springer-Verlag Berlin Heidelberg.
INDEX KEYWORDS: Annealing; Electron microscopy; Enamels; Energy gap; Field emission microscopes; Fourier transform infrared spectroscopy; High resolution transmission electron microscopy; Layered semiconductors; Molybdenum; Molybdenum compounds; Nanoparticles; Nanostructures; Scanning electron microscopy; Sulfur; Synthesis (chemical); Transmission electron microscopy; X ray diffraction analysis, Annealing temperatures; Chalcogenide semiconductors; Characteristic bands; Chemical reduction methods; Field emission scanning electron microscopy; Hexagonal structures; Homogeneous distribution; Molybdenum disulfide, Molybdenum oxide
PUBLISHER: Springer Verlag
DOI: 10.1007/s12034-014-0076-4
Lithium-doped ZnO thin films (ZnO : Lix) were prepared by spray pyrolysis method on the glass substrates for x ( x = [Li]/[Zn]) value varied between 5 and 70%. Structural, electrical and optical properties of the samples were studied by X-ray diffraction (XRD), UV-Vis-NIR spectroscopy, scanning electron microscopy (SEM), Hall effect and sheet resistance measurements. XRD results show that for x ≤ 50%, the structure of the films tends to be polycrystals of wurtzite structure with preferred direction along (0 0 2). The best crystalline order is found at x = 20% and the crystal structure is stable until x = 60%. The Hall effect results describe that Li doping leads to change in the conduction type from n- to p -type, again it changes to n-type at x = 70% and is attributed to self-compensation effect. Moreover, the carrier density was calculated in the order of 1013 cm-3. The resistivity of Li-doped films decreases until 22 Ω cm at x = 50%. Optical bandgap was reduced slightly, from 3·27 to 3·24 eV as a function of the grain size. Optical transmittance in the visible range reaches T = 97%, by increasing of Li content until x = 20%. Electrical and optical properties are coherent with structural results. © Indian Academy of Sciences.
AUTHOR KEYWORDS: Lithium; Spray pyrolysis; UV-Vis-NIR; XRD; ZnO
INDEX KEYWORDS: Crystal structure; Electric resistance measurement; Film preparation; Hall effect; Infrared devices; Lithium; Metallic films; Near infrared spectroscopy; Optical films; Optical properties; Pyrolysis; Scanning electron microscopy; Semiconductor doping; Substrates; Thin films; X ray diffraction; Zinc oxide; Zinc sulfide, Doped ZnO thin films; Electrical and optical properties; Self-compensation effects; Sheet resistance measurements; Spray pyrolysis method; UV-Vis NIR; UV-vis-NIR spectroscopy; Wurtzite structure, Spray pyrolysis
PUBLISHER: Indian Academy of Sciences
DOI: 10.1016/j.tsf.2013.12.010
Zinc oxide-Tin oxide (ZnO-SnO) binary thin films were prepared on the glass substrates by spray pyrolysis method. The variation range of the molar ratio of x = [Sn]/[Zn] considered to be changed from 5% to 50%. The films characterized by using the X-ray diffraction (XRD) technique, UV-Vis-NIR spectroscopy, Hall effect, Seebeck effect, electrical and photoconductivity measurements. Using the scanning electron microscopy (SEM) and atomic force microscopy (AFM) images the morphology and roughness of the thin films surfaces were obtained, respectively. AFM micrographs indicate the decrease of roughness by increasing the dopant (Sn) concentration (x). XRD results describe the existence of the ZnO, SnO, SnO2, ZnSnO3 and Zn2SnO4 phases for various x values. The optical band gap and transmittance were obtained from UV-Vis-NIR spectroscopy results as a function of x. The results show a general band gap narrowing which occurs with the increasing of the Sn concentration which attributed to the structure and many body effects. Moreover, comparing to ZnO thin films, the remarkable decrease of the electrical conductivity and optical transparency were observed at the low x values. The conduction type was determined by the Hall effect and thermoelectric measurements. The Seebeck effect measurements show for â̂†T ≤ 185 K, the electrons are the majority carriers, which replaced with the holes for â̂†T > 185 K. Power factor quantity was measured as a function of the Sn concentration and temperature. Furthermore, the power factor determines the best x value for the optimal electrical properties. Photoconductivity property was also observed in all samples which weakened for x ≤ 30%, and increased for the higher x values.
AUTHOR KEYWORDS: Atomic force microscopy; Binary system; Photoconductivity; Spray pyrolysis; Thermoelectricity; Tin oxide; X-ray diffraction; Zinc oxide
INDEX KEYWORDS: Band gap narrowing; Binary systems; Electrical conductivity; Optical transparency; Seebeck effect measurements; Spray pyrolysis method; Thermoelectric measurements; UV-vis-NIR spectroscopy, Atomic force microscopy; Electric power factor; Electric properties; Film preparation; Hall effect; Infrared devices; Photoconductivity; Scanning electron microscopy; Spray pyrolysis; Substrates; Systems (metallurgical); Thermoelectricity; Thin films; Tin oxides; X ray diffraction; Zinc; Zinc oxide, Tin
DOI: 10.3390/M791
As a result of three-component one-pot reaction of trans-2-benzoyl-3-(4- nitrophenyl)aziridine with 4-acetamidobenzaldehyde and ammonium acetate, N-(4-(6-(4- nitrophenyl)-4-phenyl-1,3-diazabicyclo[3.1.0]hex-3-ene-2-yl)phenyl)acetamide was obtained in good yield. The newly synthesized compound exhibit interesting photochromic behavior in the solid and solution state. The structure of the synthesized compound was confirmed by elemental analysis, 1H-NMR, 13C-NMR and UV-Visible spectral data. © 2013 by the authors; licensee MDPI, Basel, Switzerland.
AUTHOR KEYWORDS: 4-acetamidobenzaldehyde; Diazabicyclo[3.1.0]hex-3-ene; Photochromism
DOI: 10.1007/s12043-011-0257-2
In this work, ZnO thin films have been prepared by spray pyrolysis deposition method on the glass substrates. The effect of deposition parameters, such as deposition rate, substrate temperature and solution volume has been studied by X-ray diffraction (XRD) method, UV-Vis- NIR spectroscopy, scanning electron microscopy (SEM), and electrical measurements. The XRD patterns indicate polycrystalline wurtzite structure with preferred direction along (0 0 2) planes. Thin films have transparency around 90% in the visible range. The optical band gap was determined at 3.27 eV which did not change significantly. Evolution of electrical results containing the carriers' density, sheet resistance and resistivity are in agreement with structural results. All the results suggest the best deposition parameters are: deposition rate, R =3ml/min, substrate temperature, T s =450°C and thickness of the thin films t =110-130 nm. © Indian Academy of Sciences.
AUTHOR KEYWORDS: Spray pyrolysis; Thin films; X-ray diffraction; ZnO
INDEX KEYWORDS: Deposition Parameters; Electrical measurement; Glass substrates; NIR spectroscopy; Optimal parameter; Polycrystalline wurtzite; Solution volume; Spray pyrolysis deposition; Spray pyrolysis method; Substrate temperature; Visible range; XRD patterns; ZnO; ZnO thin film, Deposition; Deposition rates; Metallic films; Optical films; Scanning electron microscopy; Spray pyrolysis; Substrates; Thin films; Vapor deposition; X ray diffraction; Zinc oxide; Zinc sulfide, Film preparation
Germanium nanostructures were generated in the post annealed germanium oxide thin films. Visible and near infrared photoluminescence bands were observed in the samples annealed at 350°C and 400°C, respectively. These different luminescence ranges are attributed to the presence of the defects in oxide matrix and quantum confinement effect in the germanium nanostructures, respectively. Decay time and temperature dependence of the luminescence for different bands were investigated, which confirmed our idea about the origin of the luminescence.
AUTHOR KEYWORDS: Germanium; Nanostructures; Photoluminescence; Temperature dependence
DOI: 10.1016/j.jlumin.2009.02.013
Substoichiometric germanium oxide thin films were prepared by evaporation of GeO2 powder. The as-deposited samples showed a luminescence band in the visible range. Hydrogen was used to passivate the dangling bond defects and therefore to determine the origin of photoluminescence in the germanium oxide films. Hydrogen was introduced in the films from an electron cyclotron resonance (ECR) plasma source during or after the evaporation. The films hydrogenated during evaporation contain little oxygen because of an etching mechanism. In the post-hydrogenated films, the oxygen content is higher. With the hydrogenation treatment, the oxygen dangling bonds are suppressed. It is proposed that the photoluminescence in the visible range is attributed to the structural defects. © 2009 Elsevier B.V. All rights reserved.
AUTHOR KEYWORDS: Germanium oxide; Hydrogenation; Photoluminescence; Reactive evaporation; Thin films
INDEX KEYWORDS: Electron cyclotron resonance plasmas; Etching mechanisms; Germanium oxide; Hydrogenated films; Hydrogenation treatments; Luminescence bands; Oxygen contents; Reactive evaporation; Structural defects; Visible photoluminescences; Visible ranges, Cyclotrons; Dangling bonds; Electron cyclotron resonance; Evaporation; Germanium; Hydrogen; Hydrogenation; Oxygen; Photoluminescence; Semiconducting germanium compounds; Thin films; Vapors, Oxide films
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