In this study, we investigated the surface morphology of Au coatings using atomic force microscopy (AFM). we aimed to understand the growth mechanisms and control the nano- and micro-structure of the films to achieve desired morphological properties. The study focused on films formed by the electrodeposition technique and examined the morphology evolution as a function of film thickness. To verify the crystalline structure of the films, X-ray diffraction (XRD) technique was employed. Statistical tests were conducted to confirm that the gold thin film surfaces under investigation exhibited multifractal properties. It is found that as the film thickness increased, the multifractality of the films became more pronounced, and the nonuniformity of the height probabilities also increased. Furthermore, it was observed that surfaces with greater roughness displayed larger nonlinearity and wider width of the multifractal spectrum. The results indicated that the multifractal spectrum had a right-hook shape, distinguishing between different film thicknesses even in small sizes of hundreds of nanometers. Overall, this study provides important insights into the surface morphology of Au coatings and highlights the significance of controlling growth mechanisms for fabricating flat Au films with desired morphological properties. These findings have implications for various applications in biological, electronic, and optical devices.

Spectroscopic measurements in the range of 10 kHz to MHz at different temperatures are reported for Au/CIMgPc/Au thin film sandwich devices. The ac conductivity is found to vary with the angular frequency ω as ωn where the index n≈ 1at high frequencies indicating the predominance of a hopping conduction mechanism in this material at low temperatures and high excitation frequencies. The variation of activation energy is studied as a function of temperature and frequency. The capacitance data are analysed within the framework of the Goswami model [10].      

TaN-(Ag/Au) nanocomposite thin film was deposited on stainless steel (type 316) substrates by cylindrical DC Cosputtering technique. Samples were annealed at 400oC for different times 3, 5 and 7 minutes. Surface topography, crystalline structure, surface morphology and contact angle measurement of the prepared films were analyzed by using atomic force microscopy (AFM), X-ray diffractometry (XRD) and scanning electron microscopy (SEM) techniques, respectively. Antibacterial activity was measured by using Staphylococcus aurous bacteria at 1, 3 and 6 hours incubation times. The average size of nanoparticles measured less than 40 nm. The average size of particles and contact angle property could be controlled by annealing time and temperature. Results showed that the TaN- (Ag/Au) thin film is hydrophobic (its contact angle is more than 90 degree), so it can decrease the bacteria adhesion to the surface of the samples.

Surface plasmon resonance (SPR) is an optical technique that can be used for sensitive optical sensor and biosensor applications. Surface plasmon resonance (SPR) biosensors consisting of alternate layers of gold (Au) and Titanium dioxide (TiO2) thin film have been proposed as a high sensitivity property. Simulation analysis (in Matlab program) has been made for SPR of gold layer with thickness (10, 30 and 50 nm) and (TiO2) layer with different eight thicknesses (from 10 to 100 nm), which deposited on high refractive index glasses (N_LASF9 glass prism), while the final sensing medium is the air. The analysis achieved for different wavelengths in the visible band (500-700 nm) and different refractive index (0, 0.04, 0.08 and 0.12). The properties of SPR angle θSPR have been calculated from the incident angle θSPR plot. The SPR sensitivity (S) calculated within this study. The results show that the best sensitivity and maximum sensitivity is (116.66) for thickness TiO2=40 nm, and thickness Au =50 nm at wavelength 700 nm. for the studied refractive index.

The Qaleh-Zari specularite- rich Cu-Au-Ag deposit is located 180 Km south of Birjand. Host rocks are mainly Tertiary andesites and andesitic basalts and some Jurassic shales and sandstones. Andesitic rocks from the western region of Qaleh-Zari were dated to 40.5±2 Ma. Four trends of faults and joints are identified in the mine area.  The oldest is mineralized. Three major sub-parallel quartz veins are present. No. 2 vein is the main vein and can be traced for more than 3.5 km along strike (N40°W) and more than 350 m down dip. Paragenesis: Stage I: specularite, quartz, Fe-chlorite, chalcopyrite and sulfosalts. Specularite deposited first and forms 10 to 25 percent of the vein. Ore grade is 2 to 9% Cu, Ag 100 to 650 ppm, and Au 0.5 to 35 ppm. Propylitic alteration is dominant and epidote is very abundant. Argillic alteration is locally present. Silicification is mainly found within the vein zone. Temperature of homogenization of primary fluid inclusions in quartz associated with specularite and Cu, Ag, and Au mineralization was between 240°C and 360°C. The salinity of ore fluid was between 1.0 and 6.0 wt% equiv. NaCl and the CO2 was < 0.1 mole%. Based on the presence of hematite, chalcopyrite, Fe-rich chlorite, and, locally pyrite, and on the absence of magnetite and pyrrhotite, the ore fluid was very oxidizing. Some important differences between Qaleh-Zari and other iron-Oxides Cu-Au deposits are: (1) The salinity is very low (< 6 wt% NaCl equiv.), (2) absence of magnetite and apatite, (3) low REE and P., and 4) high grade Cu, Ag, and Au. Differences in the amount of Cu, Au, REE, P, U, F and some other elementals in iron-oxides Cu-Au deposits are related to: Tectonic setting, depth of magmatism, source of magma, degree of partial melting, physicochemical condition of melting, rate of ascending, crystal assimilation, degree of fractionation, and depth of emplacement.

In current work, new hybrid composite have been prepared by mixing gold nanocolloid physically with PVA-Fe2O3. Morphological, compositional, structure and optical properties of hybrid composites were studied by transmission electron microscope (TEM), scanning electron microscope (SEM), energy dispersive spectroscopy (EDS), Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD) and UV-visible spectroscopy (UV-VIS). XRD results showed that both Au and Fe2O3 have peaks in the structure and that confirmed by EDS and FTIR results. Microscopes results indicated the nanosized nature of prepared materials. UV–vis spectrum show absorption edge at 440 nm which relates to PVA-Fe2O3 mixed with Au which means there is a red shift after incorporation of Au in the composites. And the energy gap of composite became equal to 2.48 eV after adding Au solution.