Synthesis and characterization of Sn‑doped TiO2 flm for antibacterial applications

Simple sol–gel method has been exploited to deposit Sn-doped TiO2 thin flms on glass substrates. The resultant coatings were characterized by X-ray difraction (XRD), UV–visible techniques (UV–Vis), Fourier transform infrared spectroscopy (FTIR), and photoluminescence analysis (PL). The XRD pattern reveals an increase in crystallite size of the prepared samples with the increasing doping concentration. A decrease in doping concentrating resulted in the decrease in bandgap values. The diferent chemical bonds on these flms were identifed from their FTIR spectra. The photoluminescence analysis shows an increase in the emission peak intensity with increasing dopant concentration, and this can be attributed to the efect created due to surface states. The prepared samples were tested as antibacterial agent toward both Gram-positive and Gram-negative bacteria like S.aureus (Staphylococcus aureus) and E.coli (Escherichia coli), respectively. The size of the inhibition zones indicates that the sample shows maximum inhibitory property toward E.coli when compared to S.aureus

Optimization of Deposition Parameters on the Physical Properties of TiO2 Thin Films by Spray Pyrolysis Technique

Titanium dioxide (TiO2) thin films have been deposited on microscopic glass substrate by spray pyrolysis technique. The effect of deposition parameters such as substrate temperature, molarity (precursor concentration) and solution spray rate on the structural, surface morphological and optical properties of the films have been studied. The prepared films were characterized by X-ray diffraction (XRD), scanning electron microscope (SEM) with EDS and UV-Vis spectroscopy. The XRD patterns indicated that the films have amorphous and polycrystalline structure and the size of the crystallites have been changed from 9 to 48 nm. The optical band gap of the TiO2 films is determined to be about 3.40 to 3.65 eV to the change of deposition conditions

Applications of FTIR and 57Fe\text{}^{57}Fe Mössbauer Techniques in Studies of Recently Excavated Indian Archaeological Pottery

The Fourier transform infrared absorption spectra and $\text{}^{57}Fe$ Mössbauer spectra have been recorded at room temperature for the recently excavated archaeological pottery sherds. FTIR spectroscopy is used to estimate the lower limit of firing temperature and firing nature of the pottery sherds, and it is confirmed by the results of the Mössbauer technique results. The results show that the $\text{}^{57}Fe$ Mössbauer and FTIR spectra of few pottery sherds of Perumalpattu and Theriruveli are nearly identical, indicating that they may belong to the same origin. $\text{}^{57}Fe$ Mössbauer spectra of black coloured sherds show the presence of $Fe^{2+}$ ions which confirm the relation between the black colour in pottery and the existence of non-magnetic FeO compound, resulting from the reducing atmospheric condition during firing. FTIR results of reddish pot sherds show the presence of significant amount of $Fe_2O_3//α-Fe_2O_3$, which confirms again the relationship between the state and form of iron present in the pottery and its colour

FTIR and Mössbauer spectroscopy applied to study of archaeological artefacts from Maligaimedu, Tamil Nadu, India

860-865Archaeological potteries belonging to 300 BC collected from Maligaimedu (11°48’Lat.N; 79°35’Long.E) Tamil Nadu, India were subjected to FTIR, XRD and Mössbauer spectroscopic studies in order to characterise the clay minerals associated, their origin and technology of firing adopted by artisans. To determine the firing temperature of the potteries and to find any phase change in magnetic minerals, the pottery samples were refired to different temperatures. From FTIR studies, it is observed that these pottery samples were made up of disordered kaolinite type clay with appreciable amount of iron with a firing temperature of about 800ºC. The minerals like quartz, anorthite, orthoclase and hematite were identified using XRD. No change in the Mössbauer parameters are observed in the case of sample MGM-2 during laboratory firing up to 800°C, which indicates that original firing temperature is above 800°C. Changes in the Mössbauer spectra of sample MGM-5 during laboratory firing reveal that the laboratory firing atmosphere differs from original firing atmosphere. The presence of Fe²⁺ ion in as-received state spectra of black pottery (MGM-5) indicates that the sample was fired under reduced atmospheric condition during manufacturing. The colour of the potteries also reflects the above results

Structural, morphological and electrical properties of pulsed electrodeposited CdIn2Se4 thin films

Semiconducting CdIn2Se4 thin films have been deposited on to the conducting glass substrates using pulsed electrodeposition technique. X-ray diffraction (XRD) shows the films are polycrystalline in nature having cubic crystal structure. Energy dispersive analysis (EDAX) spectrum of the surface composition confirms the nearly stoichiometric CdIn2S4 nature of the film. Atomic force microscope (AFM) shows that the deposited films are well adherent and grains are uniformly distributed over the surface of substrate. The surface roughness and grain size increased from 0.2 nm and 12 nm to 0.7 nm and 20 nm respectively with increase of duty cycle. The films are highly transparent in the visible region with an average transmittance reaching up to 80%, which indicates the better crystalline nature with less defects. The CdIn2Se4 thin films show band gap energies of the films decreased from 3.12 eV to 3.77 eV. Keywords: Structural studies, XPS, AFM, Optical properties and photosensitivit

Application of FTIR and Moss bauer spectroscopy in analysis of some South Indian archaeological potteries

833-838<span style="font-size: 15.0pt;mso-bidi-font-size:8.0pt;font-family:" times="" new="" roman","serif""="">FTIR, XRD and room temperature Mossbauer spectra have been recorded for the recently excavated archaeological potteries from Sriperumbudur, Elichanur (Tamil Nadu ) and Thiruvanchikulam (Kerala) . When firing the clay based materials like potteries, bricks and tiles etc. , the presence of a few per cent of iron undergoes characteristic changes in its physical and chemical states depending upon the maximum firing temperature reached and kiln atmosphere, which can he followed by using FTIR and Mossbauer spectroscopic techniques. From the above techniques. the lower limit of firing temperature. firing atmosphere and type or clay used for the production of archaeological potteries were well established. </span

Investigation of granite waste incorporated clay brick as a building material

Abstract The incorporation of various industrial waste materials as additives in the manufacture of clay-based products has been attracting a growing interest from researchers in recent years and is becoming common practice. The present work reports the changes in the behaviour of the clay material used in the brick industry due to additions of a granite sawing powder wastes, generated from ornamental stone processing industry in Madurai region, South India. The raw materials were characterized with respect to their chemical composition by XRF, mineralogical composition by XRD, particle size distribution and plasticity. Mixtures of clay and waste material (10-50 wt. %) were moulded by extrusion and sintered at temperature ranging from 600 to 900°C. Results of technological tests indicated that the granite waste proportion and firing temperature were the two key factors determining the quality of bricks. With 30 wt. % granite waste content, the reformulated briquette specimens sintered at 900°C exhibited better values of water absorption, porosity, bulk density and mechanical strength than the normal clay bricks produced in the industr

Spectroscopic and rock magnetic studies on some ancient Indian pottery samples

AbstractIn this study, the ancient potteries from Tamilnadu (Nedungur: Lat.10° 57′N; Long.77°51′E) were collected and investigated for their chemical and mineralogical characteristics to estimate their firing temperature and firing atmosphere. The physical and chemical state of iron (Fe2+/Fe3+) and iron oxide phases obtained using Mössbauer spectra were used to establish the temperature and atmosphere of firing. The clay mineral type and its structural deformation due to firing were established using X-Ray Diffraction (XRD), X-Ray Fluorescence (XRF) and Fourier Transform Infrared (FTIR) Spectroscopy. The data collected from these techniques show that quartz was the predominant mineral, followed by traces of albite, orthoclase and Fe-bearing minerals (hematite and magnetite) and suggested that the firing temperature of potteries lies in the range of 600–800 °C in oxidizing atmosphere. The mineral types and domain states of the constituent magnetic fine particles were elucidated using the variation of susceptibility at various frequencies and temperature under low field. An attempt has also been made to correlate the magnetic parameters from the percentage of Fe2+/Fe3+ and iron oxides. The information obtained paves a way for a better understanding of the technological development that took place in the ancient past and also the suitability of the samples for the determination of reliable ancient geomagnetic field intensity values