M. Zahedifar
Institute of Nano Science and Nano Technology, University of Kashan, Kashan, P. O. Box. 87317–51167, Iran | Faculty of Physics, University of Kashan, Kashan, P. O. Box. 87317–51167, Iran
[ 1 ] - Luminescence Properties Of Pure CaSO4 Nanoparticles Produced By Co- Precipitation Method
Thermoluminecsence (TL) characteristics of pure CaSO4 nanoparticles produced by co-precipitation method are presented. The formation of the nanoparticles was confirmed by X-ray diffraction (XRD) and scanning electron microscope (SEM). TL glow curve of this phosphor, exposed to gamma radiation exhibits five overlapping glow peaks in the complex glow curve at 463, 470, 483, 498 and521(K) respecti...
[ 2 ] - Gold catalytic Growth of Germanium Nanowires by chemical vapour deposition method
Germanium nanowires (GeNWs) were synthesized using chemical vapor deposition (CVD) based on vapor–liquid–solid (VLS) mechanism with Au nanoparticles as catalyst and germanium tetrachloride (GeCl4) as a precursor of germanium. Au catalysts were deposited on silicon wafer as a thin film, firstly by sputtering technique and secondly by submerging the silicon substrates in Au colloidal s...
[ 3 ] - Preparation and Characterization of Downconversion Luminescent LaVO4: Tm3+ , Yb3+ and Tm3+ /Yb3+ Nanosheets
Tm3+ , Yb3+ and Tm3+ /Yb3+ doped LaVO4 nanostructures were synthe- sized for the first time by using the hydrothermal method with the aid of La(CH3CO2)3 as lanthanum source in presence of oleic acid as surfactant. The products were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), photoluminescence (PL) spectroscopy and ...
[ 4 ] - Thermoluminescece properties of BeO:Mg nanoparticles produced by sol-gel method
Beryllium oxide (BeO) nanopowder was synthesized using sol-gel method and the effects of changes of chemical reagents were investigated. Because of tissue equivalence and other outstanding thermoluminescence (TL) properties of the bulk material in X and γ dosimetry, the applicability of this nanostructure in TL dosimetry was studied following irradiation to the 137 C...
[ 5 ] - سنتز نانوذرات منیزیم سولفات آلاییده شده با مس به روش هیدروترمال و بررسی خاصیت ترمولومینسانس آن‌ها در پرتودهی گاما
In this research MgSO4:Cu nanoparticles was synthesized for the first time by hydrothermal method. The size of the produced nanoparticles calculated by scherrer equation was about 36 nm using XRD pattern which was in agreement with that of SEM analysis. Thermoluminescence (TL) properties of the MgSO4:Cu nanoparticles was investigated in gamma irradiation by 60Co source. Optimum amount of impuri...
[ 6 ] - تعیین پارامترهای فروکشی دمایی دزیمتر ترمولومینسانس (TLD-100) LiF:Mg,Ti
Thermal quenching is a known and important effect which should be taken into account in studying thermoluminescence (TL) phenomenon. This effect causes the probability of non-radiative recombinations to be increased with raising temperature in TL process. This article deals with changes of the TL glow curve of LiF:Mg, Ti (TLD-100) with heating rate. It was observed that the main dosimetry peak ...
[ 7 ] - سنتز نانوذرات SrF2 با ناخالصی Yb و بررسی خصوصیات دزیمتری آن
Nanoparticles of Yb-doped SrF2 were synthesized by co-precipitation method. The formation of nanostructures was confirmed by X-ray diffraction (XRD) pattern. The particle size of about 46 nm was calculated from XRD data. The shape and size of SrF2:Yb nanoparticles were also observed by scanning electron microscope (SEM). The computerized glow curve deconvolution (CGCD) method was employed to det...
[ 8 ] - شبیه سازی قله‌های ترمولومینسانس نانوذراتLiF:Mg,Cu,P با استفاده از روش مونت کارلو
The thermoluminescence (TL) glow peaks of nanoparticles was simulated by a the Monte Carlo method in which all the ordinary as well as anomalous transitions between the nanoparticle clusters are taken into account. The adjustable parameters are activation energy and frequency factor of the trap, both radiative and nonradiative recombination, direct recombination from trap to recombi...
[ 9 ] - ساخت بلور سدیم کلرید خالص به روش همرسوبی در اندازه‌های متفاوت و بررسی خواص ترمولومینسانس آن در پرتودهی با گاما
In this research, Pure Sodium chloride (NaCl) Nano and micro particles were produced for the first time by using the surfactant in co-precipitation method. X-ray diffraction (XRD) and scanning electron microscope (SEM) were utilized to analyze the shape and size of the synthesized material. The role of CTAB surfactant on morphology of particles was also investigated. The results show that CTAB ...
[ 10 ] - تفکیک دز نوترون و گاما در میدان‌های آمیختۀ( n-γ (Am-Be, 137Cs) با استفاده از دزیمتر TLD-500
The possibility of employing α-Al2O3:C (TLD-500) for estimation of gamma dose in mixed n-γ radiation fields by two peak method has investigated. It was found that the main peak can be reliably deconvoluted to two component glow peaks. The ratio of peak 2 to peak 1 in pure gamma ray radiation field (137Cs) is 1.49 whereas irradiation by Am-Be neutrons results in a ratio of 1.12. The precision of...
[ 11 ] - ارزیابی پرتوگیری مردم از پرتوهای طبیعی زمینه گاما و رادن در شهر کاشان
In this research work public dose of Kashan inhabitants has been evaluated. Average annual effective dose due to inhalation of radon gas as well as external exposure to gamma rays have been evaluated to be 2.77±0.22 mSv and 0.97±0.05 mSv respectively. This leads to average annual public dose of 3.74 ± 0.22 mSv. Passive methods such as TLD pellets of LiF:Mg,Cu,P and polycarb...
[ 12 ] - اندازه‌گیری غلظت رادن در برخی ساختمان‌های مسکونی شهر کاشان
Radon concentration was measured in some dwellings in Kashan city. List of buildings was chosen randomly including old buildings made up of mud brick & clay and new buildings constructed with bricks and cement. Population weighted Radon concentration survey was followed and measurements were carried out using polycarbonate (lexan) track detector at the levels of basement to second floor of the ...
[ 13 ] - تعیین میزان دز جذب‌شدۀ پرتو گاما به روش PTTL با استفاده از آشکارساز α-Al2O3:C
Phototransferred thermoluminescence (PTTL) was used to reeestimate the absorbed gamma dose in α-Al2O3:C dosimeter. The PTTL response of this phosphor for different UVB irradiation times was investigated. The results show a linear PTTL response for gamma absorbed doses from 0.1 to 14 mGy. Because of high PTTL sensitivity in this phosphor, the low limit of re-estimated gamma dose using PTTL metho...
[ 14 ] - ساخت نانوبلور لیتیوم تترا بورات آلاییده با منیزیم به روش احتراقی و بررسی رفتار لومینسانس آن
Lithium tetraborate nanoparticles were synthesized by combustion method. The shape and size of nanoparticles were determined by scanning electron microscopy (SEM). X-ray diffraction pattern (XRD) confirmed the formation of lithium tetraborate nanocrystals. Thermoluminescence (TL) glow curve of the produced nanoparticles following irradiating with gamma radiation demonstrates five overlapping gl...
[ 15 ] - ساخت دزیمتر گرماتاب LiF:Mg,Cu,P و بررسی تأثیر ناخالصی مس بر خصوصیات گرماتابی آن
LiF powder having particle size of 50-200 µm doped with Mg, Cu and P impurities was produced using melting method. The whole construction process was conducted in a nitrogen atmosphere. The effect of Cu impurity on the thermoluminescence glow curve was investigated and the appropriate amount of Cu was determined. The TL properties of the fabricated phosphor was compared to commercial LiF:Mg,Cu,...
[ 16 ] - ساخت نانوذرات CaF2 با ناخالصی Tl و بررسی خصوصیات دزیمتری آن
Thallium doped calcium fluoride (CaF2:Tl) nanoparticles were produced for the first time by using the hydrothermal method. X-ray diffraction (XRD) and scanning electron microscope (SEM) were utilized to analyze the synthesized material. The particle size of about 45 nm was evaluated using XRD data which was supported by the SEM images. Thermoluminescence glow curve of this nanophosphor exhibits...
[ 17 ] - سالیابی نمونه سفالی به دست آمده از کاوش‌های باستان‌شناسی در مرکز ایران به روش ترمولومینسانس
Archeology dating of sample obtained from Vigoldistrict (center of Iran) was done using thermoluminecencse (TL) technique. The plateau region was determinedby comparing the TL glow curves of the samples received natural dose and those samples received natural dose plus gamma dosefrom the60Co source. The total equivalent dose of 10.17 Gy was obtained by the use of TL dose response of the samples...
[ 18 ] - ساخت نانوذرات ZnS:Mn و بررسی توانایی تولید گونه‌های فعال اکسیژن توسط آن‌ها
امروزه نانوذرات نیمه‌هادی، توجه بسیاری را در شاخه‌های نانو پزشکی به خود جلب کرده‌اند. در این تحقیق توانایی نانوذرات ZnS:Mn در تولید گونه‌های فعال اکسیژن شامل رادیکال هیدروکسیل بررسی شد و همچنین روش سنتز نانوذرات ZnS:Mn گزارش شد. نانوذرات ZnS:Mn به روش همرسوبی ساخته شد. تحریک نانوذرات توسط پرتو UV انجام گرفت. مشخصه‌یابی ساختار نانوذرات تهیه شده با استفاده از آنالیزهای XRD, TEM، SEM و PL انجام گ...
[ 19 ] - یک مدل جدید ترمولومینسانس با توزیع پیوسته انرژی مراکز گیراندازی
A mixed order model is proposed for describing thermoluminescence (TL) glow peaks with continuous and uniform distribution of trapping states. It is shown that the presented function reduces to the simple known models at the limiting cases. The function for TL intensity has been introduced in terms of intensity and temperature of the peak maximum. These parameters can easily be estimated from t...
[ 20 ] - ساخت دزیمتر لیتیم فلوراید آلاییده با استرانسیم و سریم به روش ذوب و مطالعه خواص ترمولومینسانس آن
In this work, lithium fluoride doped with impurities of Sr and Ce, was produced using melting method and its thermoluminescence (TL) properties was investigated. The optimized values of 0.5 mol% of Sr and 0.1 mol% of Ce were obtained for the most TL sensitivity. Reusability of the prepared samples has been investigated for 5 cycles of annealing, irradiation and reading and no considerable chang...
[ 21 ] - Investigation of the production of free radicals in ultraviolet irradiation using SnO2:Eu nanoparticles
In studying the ultraviolet (UV) radiation, one of the important factors is the possibility of generating a variety of free radicals inside the body by these radiations. In this paper, a method of estimating the amount of hydroxyl radicals produced by ultraviolet rays was investigated using nanoparticles of tin oxide doped with uropium. In this method, the change in absorption intensity of meth...
[ 22 ] - Recovery of thermoluminescence sensitivity in CaF2:Mn (TLD-400) dosimeter under heating process
In order to recovery the thermoluminescence (TL) sensitivity of CaF2:Mn (TLD-400) thermoluminescent dosimeter it was exposed to high gamma radiation dose of 10kGy, then by applying standard annealing followed by irradiation to 1Gy gamma dose, the TL signal was recorded . The TL response reduced due to the damage effect of high dose irradiation in comparison with control dosimeter with received ...
[ 23 ] - Synthesis of strontium borate doped with Pb by solid state method and characterization of its thermoluminescent glow curve
Strontium Tetraborate doped with Lead SrB4O7:Pb powder was prepared by solid state method. The formation of Strontium Tetraborate compound was analyzed by X-ray diffraction (XRD) and Scanning Electron Microscopy (SEM). Thermoluminescence Glow Curve of gamma irradiated sample was investigated in order to use as a thermoluminescent dosimeter. Because of excellent mechanical properties, non-hygros...
[ 24 ] - Thermoluminescence characteristics and kinetic analysis of copper doped magnesium sulfate in gamma irradiation
MgSO4:Cu phosphor was synthesized by solid state method. Optimum concentration of copper was determined at 0.1 mol%. Thermoluminescence characteristics of MgSO4:Cu was studied following gamma irradiation. A linear dose response was observed in dose range of 1Gy to 500Gy. Reusability of this sample was tested after 10 cycles of gamma irradiation and it revealed that the intensity remains approxi...
نویسندگان همکار