Nanocrystalline cobalt ferrite powder has been synthesised by citrate precursor and co-precipitation methods. Structural characterization of the samples has been carried out using powder X-ray diffraction, Fourier transform infrared spectroscopy (FT-IR) and field emission scanning electron microscope (FE-SEM). Distribution of cations among the two interstitial sites (tetrahedral and octahedral sites) has been estimated by analysing the powder X-ray diffraction patterns by employing RIETVELD refinement technique, and the results reveal the existence of samples as a mixed type spinel with cubic structure. It is observed that the distribution of cations and structural parameters are strongly dependent on synthesis method and annealing temperature. The vibrational modes of the octahedral and tetrahedral metal complex in the sample have been examined using FT-IR in the wave number range of 390 to 750 cm-1, and it shows an absorption band within this range, which confirms the spinel structure of the sample. The existence of constituents in the sample, i.e., Co, Fe and O has been authenticated using energy dispersive spectrum with the help of a FE-SEM.

The particle size distribution of the resultant cobalt ferrite samples was determined from Scanning Electron Microscopy (SEM) images using the granulometry image analysis method. The results showed the nanosized particles of the samples. The X-Ray Diffraction (XRD) patterns of samples were also analyzed by RIETVELD refinement method. The results indicated that the precipitated sample at 95 oC had cubic cobalt ferrite structure with F3dm: 3 space group and high crystallinity. The lattice parameters, microstrain and crystallite size of samples were also calculated from the XRD pattern. With increasing the precipitation temperature, the crystallite and particle sizes were increased while the lattice parameter and microstrain were decreased. Regarding the results, it can be concluded that the lattice parrameter of cobalt ferrite has a diverse relationship with crystallite size.

In the current study, the two samples were taken kindly from the Sungun copper ore. Initially, more contemporary preparations on the samples were made to intensify their X-Ray patterns. Then, clay minerals were identified by inspecting their XRD patterns. To determine the quantity of clay minerals their XRD profiles were simulated using RIETVELD method based on their crystallographic information. In addition, standard samples using high purity components of interest clay minerals were made by mixing for a given weight per cent. The obtained results indicated that the main types of clay minerals in the Sungun ore samples are Illite, Kaolinite and Muscovite. The comparison of the results revealed that the RIETVELD method yields more valid and reliable results rather than the standard. The maximum error in determination of clay minerals for standard samples by using the RIETVELD method was 3.12%. The results proved that applying whole profile fitting on XRD patterns give more reliable data than using single line fitting of XRD patterns. Further, the separation of clay minerals via contemporary preparations from the samples is crucial commission since other phases into the samples decrease dramatically the intensity and broadening of clay minerals peaks in XRD patterns, subsequently increasing the simulation error.

In this article, we have employed GSAS software to do Reitveld profile refinement on XRD patterns from H-Tc superconductor powder YBa2-xKxCu3O7-y (0<x,y<1) samples. Increasing the Potassium doping content of the sample, x, causes some changes in the XRD patterns such as creating new peaks and also deteriorating of goodness of the refinement, c2. On the other hand, substituting of K instead of Ba led to oxygen depletion and also lowering the Ba (K) plane position along the Z direction (||c). The structural phase ratio of tetragonal to orthorhombic increased and it means that the superconductivity exist even in samples with dominant tetragonal phase.

Reitveld full profile refinement analysis has been done on Synchrotron diffraction data from a powder sample of YBCOx at RT and 500oC. Anisotropic peak broadening for (h00) and (hh0) lines has been observed by Williamson-Hall (W-H) analysis and that is in agreement with formation of twin's microstructures along (110) crystal planes in the sample. In addition, size and strain of the crystallites has been inferred in our study also.

Nanostructured NiSb2O6 samples were synthesized via solid state reactions at 600, 700 and 800 ° C using Sb2O3, Ni(CH3COO)2. 2H2O and Ni(NO3)2. 6H2O as the raw materials. Parameters of reaction temperature and raw material type were investigated for the crystal phase growth study. The synthesized nanomaterials were characterized by X-ray powder diffraction (XRPD) technique, fourier-transform infrared (FTIR) spectroscopy. Brunauer– Emmett– Teller (BET) and Barrett-Joyner-Halenda (BJH) methods were used to investigate the textural properties of the obtained samples. RIETVELD analyses showed that the obtained materials were crystallized well with a tetragonal crystal structure with the space group of P42/mnm. The lattice parameters of the targets were about a = b = 4. 64 Å and c = 9. 22 Å . The data revealed that the crystal phase purity of the as-synthesized nanomaterials increased with raising the reaction temperature from 600 to 800 ° C. Besides, the data indicated that the synthesis reactions using Ni(NO3)2. 6H2O generated a better crystalline growth and purity compared to Ni(CH3COO)2. 2H2O raw material in a certain reaction temperature. The morphologies of the synthesized materials were studied by field emission scanning electron microscopy (FESEM) technique. The FESEM images showed that the homogeneity of the synthesized powder was improved when Ni(NO3)2. 6H2O was used as the raw material. Ultraviolet-visible spectra showed that the synthesized NiSb2O6 nanomaterials had a strong light absorption in the ultraviolet light region. The calculated direct optical band gaps tendency showed that the band gaps increased with increasing the reaction temperature.

In this research work, powder hydroxyapatite samples were synthesized using a solid-state reaction method to investigate the annealing effect. The crystal structure was carried out by XRD system produced data, and the RIETVELD method using MAUD software. The samples were irradiated in different radiation absorbed doses up to 1500 Gy and their thermoluminescence properties including glow curve, response, fading effect and reproducibility were investigated from dosimetry point of view. The results showed that the annealing temperature significantly affects the crystal structure and thermoluminescence dosimetry response of hydroxyapatite samples, consequently. It was concluded that high temperature annealing process can lead to formation of ,-TCP crystal phase during the synthesis of hydroxyapatite. Percentage of this formed phase increases with rising the temperature, and finally leads to increasing of the thermoluminescence response. It was concludded that in the solid state reaction method to increasing the TL response, it is better to use high annealing temperature for the synthesis of hydroxyapatite sample.

Strontium hexaferrite (SrFe12O19) nanopowders have been synthesized using sol-gel auto combustion route. Ferrite precursors were obtained from aqueous mixtures of strontium nitrate and ferric nitrate nonahydrate. Citric acid (C6H8O7), was added to the mixed solution as fuel. The effect of calcination temperature on the structural, morphological, magnetic properties and phase formation of synthesized SrFe12O19 nanopowder was investigated and discussed in details. The material properties were studied employing X-ray diffraction (XRD), Raman spectroscopy, SEM, and a vibrating-sample magnetometer (VSM). The calcined products and the formation of crystalline phase were analyzed via XRD technique which revealed the SrM single phase formation at calcined temperature 1100oC with a crystallite size of 76.107 nm. The RIETVELD refinement technique as applied in the Fullprof program was utilized for determining the resulting crystalline phase’s amounts, lattice parameters, Bragg R-factor and refined structure value χ2. Raman analysis verified the development of the whole crystallographic hexaferrite locations and the whole peaks in the sample related to Raman vibration modes as well as M-type structures.   Additionally, the resulted outcomes verified that the prepared material was SrFe12O19 and its density (ρx) reduced as its calcination temperature increased up to 1100°C. The sample material’s magnetic analysis at the room temperature elucidated a higher coercivity value of (4610 Oe), a saturation magnetization of (66.285 emu/g), and a remnant of 38.90 emu/g.

A Bi2O3 nanomaterial was fabricated by a facile and low temperature solid state method using a basic bismuth nitrate raw compound at 400 ˚, C and 14 h. RIETVELD analysis data indicated that α,-Bi2O3 was crystallized well in monoclinic crystal system with the space group of P121/c1. The morphology of the synthesized material was studied by field emission scanning electron microscope (FESEM). The direct band gap energy (Eg) value was calculated by ultraviolet –,visible (UV-Vis) spectroscopy. The peaks at 400 –,550 cm-1 are assigned to oxygen –,metal –,oxygen (O-M-O) vibrations. The data showed that the Eg of the synthesized material was about 2. 2 eV. In addition, the vibrating-sample magnetometer (VSM) analysis data confirmed that the synthesized sample had ferromagnetic behavior. Further, gas sensing property of the synthesized Bi2O3 nanomaterial for carbon monoxide gas was studied, and the data confirmed the good sensitivity of the prepared sensor at low CO concentrations.