Microstructural analysis of neutron-irradiation induced changes in polyester fibre studied using EPMA

Electron microscopy is an important characterization technique for the study of textile fibre as it gives more information on fabric wear, nature of fibre fracture, chemical degradation, abrasion, fatigue and many others. Electron Probe Micro Analyzer (EPMA) micrographs of virgin and some neutron-irradiated samples (graphite coated) are discussed. The filament diameter, D, of virgin PET fibre obtained from EPMA study was 12.5 µn. The surface topography of single filament distinctly reveals the core and sheath parts of the filament. The core diameter of the virgin fibre was estimated to be 1.43 µm. The fibre irradiated at fluence 1 × 1012 n/cm2 shows radiation induced sphere like polymer balls or spherulites of diameter 2.27 µm in the expanded core region. Due to irradiation, the sheath area crosslinks with expanded core region, which may be responsible for increase of strength and hardness of the polymer materials. Moreover, the micrograph at 3000 X magnifications clearly shows that there is no preferred orientation of the polymer in any direction confirming the isotropic nature of the sample.Microstructural analysis of neutron-irradiation induced changes in polyester fibre studied using EPMA Biswajit Mallick1*, Ramesh Chandra Behera2, Simanchal Panigrahi1, Tanmaya Badapanda1, Biswanath Parija1, Banita Behera1, Manas Panigrahi1 and Madhumita Sarangi2 1Department of Physics, National Institute of Technology, Rourkela-769 008, Orissa, India 2Department of Metallurgical and Materials Engineering, National Institute of Technology, Rourkela-769 008, Orissa, India E-mail : [email protected] of Physics, National Institute of Technology, Rourkela-769 008, Orissa, India 2Department of Metallurgical and Materials Engineering, National Institute of Technology, Rourkela-769 008, Orissa, Indi

Structural and electromechanical study of Bi0.5Na0.5TiO3-BaTiO3 solid-solutions

Solid solution of (1-x)Bi0.5Na0.5TiO3–xBaTiO3 have been synthesized via conventional solid-state reaction route. Structural changes of the solid-solutions were investigated by using X-ray diffraction, Rietveld refinement Raman spectroscopy and piezoelectric studies. X-ray diffraction analysis shows a distinct 002/200 peak splitting appearing at x = 0.07 showing the coexistence of rhombohedral and tetragonal phase. Raman spectroscopy shows a splitting of (TO3) mode at x = 0.07 confirming the presence of the morphotropic phase boundary region. The dominant bands in the Raman spectra are analysed by observing the changes in their respective peak positions, widths and intensities as the x increases. The piezoelectric properties of the solid solution increase with rise in BaTiO3 content and shows optimum value at x = 0.07 owing to the co-existence of two ferroelectric phases. Based on these results, it is suggested that the morphotropic phase boundary in the studied system lies in the composition x = 0.07