THERMOGRAVIMETRIC ANALYSIS OF NANO CRYSTALLINE CERAMIC PbSrCaCuO

2014

Nano crystalline ceramic PbSrBaTiO is prepared from mechanically mixed powders of high purity raw materials. Mechanical mixing is done by high-energy ball milling and attrition milling process. The prepared material is then calcined in ambient air and optimum temperature so that the desired homogeneity and phase formation is acquired. EDX analysis is done to find out the elemental composition. Using TGA, DTA and DSC thermal behaviour of the sample at a high temperature is studied.

JOURNAL OF ADVANCES IN PHYSICS, 2014

ABSTRACTNano-crystalline Ceramic PbSrCaCuO have been prepared by a high-energy ball milling process through mechanically assisted synthesis. The prepared sample was then subjected to calcinations to acquire the desired homogeneity and phase formation. UV-VIS analysis of the sample was carried to study the optical properties of the sample. The band gap energy of the sample shows a marked variation in their value with the increase in temperature. The refractive index n was calculated and the results obtained is plotted with the wavelength. The refractive-index curves also show a systematic variation with temperature.

Crystal Structure Theory and Applications, 2014

High-temperature superconductivity in ceramic oxides is a new technology in which advances are occurring at a rapid pace. Here, the author describes some properties of a new nano crystalline ceramic Type II superconductor, PbSrCaCuO. Type II superconductors are usually made of metal alloys or complex oxide ceramics. The PSCCO perovskite phase structure was prepared by the conventional solid state reaction technique. In order to show the viability of the proposed method, super-conducting powder was prepared in special furnace. The sample was analyzed by X-ray Diffraction (XRD), Particle size determination, SEM and EDX. The comparison of XRD results with JCPDS files confirmed the orthorhombic structure of the sample with a ≠ b ≠ c and α = β = γ = 90˚. Scanning electron microscopy (SEM) studies revealed that its particle size is in the nanometer range. It also confirmed the calculated value of particle size from Debye Scherrer's formula. EDX spectrum shows the elements of the sample. X-ray instrumental peak broadening analysis was used to evaluate the size and lattice strain by the Williamson-Hall Plot method.

A novel, low temperature synthesis technique is developed for fabrication of nanocrystalline CaCu 3 Ti 4 O 12 ceramic powders, using inexpensive and easily available reagents. Structural and microstructural characterization was undertaken by X-ray diffraction, scanning electron microscopy and transmission electron microscopy. The confirmation regarding the phase formation was done using the Reitveld analysis. The compound belongs to the cubic system with the lattice parameter a = 7.3985 Å, which agrees well with the values reported in the literature. The particles formed were spherical in shape, with the average size of 70 nm.

Advances in Ceramics - Synthesis and Characterization, Processing and Specific Applications, 2011

Advances in Ceramics-Synthesis and Characterization, Processing and Specific Applications 128 offers the advantage of being able to place the dosimeters in outdoor stations for solar radiation monitoring, without requiring any additional special monitoring or logistical considerations, ceramics as well as, undoped and RE doped ZrO 2 and aluminium oxide are suggested by us as a suitable TLD material to accomplish this task. 2. Synthesis and processing of materials and ceramics Ceramic luminescent is a material that emits light after absorbing external energy (e.g. ultraviolet radiation, X-rays, gamma rays). This kind of material has been widely applied in the fields of illumination, display, X-ray detectors, etc. However, with the development of sciences and technology, lots of the conventional phosphors have been unable to meet the requirements of current luminescent applications. In recent years, researchers have focused their work on the improvement of the luminescence property of traditional phosphors and preparation of new luminescent material. In this sense, different preparation methods and properties of several TL materials have been studied so far and it was found that metal oxides doped with proper activators constitute a class of promising TL phosphors. 2.1 Microstructured materials Traditionally, CaSO 4 :Dy thermoluminescent materials are used extensively for the radiation dosimetry purpose due to low cost, high sensitivity, and very high storage stability in ambient climatic conditions (Azorín, 1990). However, the integrated processes of sintering and microstructure development in a crystalline compound are so complex that even after 50 years of research. Over this time, research on luminescence micro and nanocrystalline materials has been greatly accelerated by the advances in the ability to manipulate structures at molecular or atomic level (Rivera et al., 2010a; Salah et al., 2006a). Most of the studies have been directed towards the synthesis, characterization, and application of these systems as structural and optical or electronic materials (Salah et al., 2006b). Many ceramic compounds are most easily prepared in a powder form. Powders-based processing allow the fabrication of ceramics at temperatures that are hundreds of Celsius degrees lower than are possible by the melt processes often used for metals and polymers. Powder processing also results in ceramic components with microstructures that are ideal for luminescent applications. Both chemical and morphological control of many advanced ceramic powders have been achieved at the commercial level, for compounds including aluminium oxide, zirconium oxide polycrystalline, silica, and barium titanate. Research in ceramics processing is extremely diverse, and encompasses all activities which contribute to the science and technology of fabricating ceramic materials in a useful form. Ceramics manufacturing has historically been based primarily on powder processes. The basic fabrication steps in producing such a ceramic component consist of powder synthesis, powder forming, and sintering. An important role of basic research is to address the chemical and physical phenomena involved in each of these steps. A largely qualitative understanding of sintering and microstructure development has evolved over recent years, leading to successful control of the sintered microstructure of many structural and functional ceramics, i.e. translucent alumina, toughened zirconia. 2.2 Nanostructured materials The integration of powders of controlled size and shape with handling procedures based on principles of colloid and interfacial science has permitted the development of new powder www.intechopen.com Synthesis and Thermoluminescent Characterization of Ceramics Materials 129 processing paradigms. For example, the improvement in mechanical properties of structural ceramics has been enabled by better powders and more thoughtful processing to avoid the deleterious effects of aggregates. Powders with particle sizes on the nanometer scale have the potential for further decreasing firing temperatures, and thereby developing new applications. The development of new tools suitable for nanoscale particles such as computational chemistry and improved understanding of colloidal behaviour at the nanoscale are required. Furthermore, there is a need to develop processing schemes that utilize more environmentally-benign aqueous systems rather than organic solvents. 2.3 Routes for solution-based preparation Various methods to synthesize ceramics materials have been reported based on traditional approaches to modify the band structure of the materials as well as the characteristics of their trapping centres. Interest in synthesizing based ceramics has increased considerably in recent years as possible technological applications triggered a wide variety of research activities on this material. 2.3.1 Precipitation method Currently, nanotechnology and nanomaterials have attracted several researchers from different fields (Heuer & Hobbs, 1981), especially from the field of luminescence. It has been found that the physical properties of individual nanoparticles can be very different from those of their bulk counterparts. Recent studies on different luminescent nanomaterials have showed that they have a potential application in dosimetry of ionizing radiations for the measurements both of low and high doses using the thermoluminescence (TL) technique, where the conventional microcrystalline phosphors saturate (Kumar et al., 1994; Rivera et al., 2007b). For high doses, the saturation occurs due to the ionized zones overlapping each other in some micromaterial. The TL results of the reported nanomaterials have revealed very imperative characteristics such as high sensitivity and saturation at very high doses. Among the preparation methods of luminescent materials, homogeneous precipitation method not only has the advantages of simple process, convenient for doping and low production cost, but also can prepare uniform and small sized particles, because the precipitants are formed slowly and homogeneously throughout the solution during the precipitation process.

Crystallography Reports, 2013

By means of the reduction of Pb(II) and Se(IV) with hydrazine, oval monodispersed PbSe nano particles characterized by sizes ~100 nm and the cubic symmetry were obtained. Their compaction and sin tering into quasi ceramic state were performed. The samples were investigated by means of scanning electron microscopy, X ray diffraction and FTIR spectroscopy. The results obtained are discussed.

TJPRC, 2014

This study aims to understand thoroughly the effects of calcining and sintering conditions on the relative permittivity and sintering behaviors of the solid solution method of preparing BSTs. BST (BaxSr1-xTiO3, x = 0.6, 0.7,0.8 and 0.9) was synthesized using an established solid-state reaction method [R.K. Roeder, E.B. Slamovich, Stoichiometry control and phase selection in hydrothermally derived BaxSr1-xTiO3 powders, J. Am. Ceram. Soc. 82 (7) (1999) 1655, R. Ganesh, E. Goo, Microstructure and dielectric characteristics of PbxBa0.5-xSr0.5TiO3 ceramics, J. Am. Ceram. Soc. 79 (1996) 225, J.W. Liou, B.S. Chiou, Effect of direct-current biasing on the dielectric properties of barium strontium titanate, J.Am. Ceram. Soc. 80 (12) (1997) 3093, T. Noh, S. Kim, C. Lee, Chemical preparation of barium–strontium titanate, Bull. Korean. Chem. Soc. 16 (1995) 1180]. From XRD, the tetragonal perovskite phase formation was confirmed. The lattice parameters a and c were calculated from the XRD data. As a function of frequency and temperature, the dielectric constant and dielectric loss were studied in the frequency range 1 kHz to 1 MHz. When the strontium content in the sample increases, unit cell volume decreases.

Materials Science Forum, 2010

Ceramic materials have properties defined by their chemical and micro-structural composition. The quantification of the crystalline phases is a fundamental stage in the determination of the structure, properties and applications of a ceramic material. Within this context, this study aims is the quantitative determination of the crystalline phases of the ceramic materials developed with addition of mineral coal bottom ash, utilizing the X ray diffraction technique, through the method proposed by Rietveld. For the formulation of the ceramic mixtures a {3,3} simplex-lattice design was used, giving ten formulations of three components (two different types of clays and coal bottom ash). The crystalline phases identified in the ceramic materials after sintering at 1150oC during two hours are: quartz, tridimite, mullite and hematite. The proposed methodology utilizing the Rietveld method for the quantification relating to crystalline phases of the materials was shown to be adequate and eff...

Gravitasi

Ceramics globally has been developed by various materials and methods to find suitable ceramics for specific applications. This paper discusses development of several methods in ceramic preparation such as hot-pressing, sintering, co-precipitation, and solid-state method. In 2001 up to 2019, hot-pressing method was used to manufacture ceramic B4C and SiAlCO as raw material doping by (W, Ti)C. In 2002 up to 2018 sintering method by using fly ash as raw material with an additional K2CO3, Na2CO3, and Nb2O5. In 2008, co-precipitation method was used for CaCu3Ti4O12 (CCTO) as raw material until 2019, and then ZrO2-Al2O3 as a newcomer ceramic material. From 2001 up to 2017, solid-state method was used with microwave for MgTiO and 3-CaTiO with Eu and (Lu, Gd) 2O3 as a dopant. This paper provided four methods and the materials from reported references from 2000 up to now, as guidance in producing specific functional ceramics in the future.