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The 100% phase pure calcium silicate nanoparticles (CSNPs) of the α‐wollastonite phase by hydrothermal synthesis is achieved first. Next this work reports the first‐ever microwave‐assisted low temperature synthesis of calcium silicate‐cellulose nanograss composites. The characterization by FESEM studies confirm that calcium silicate‐cellulose composites possess the nanograss like morphology spread over the matrix of calcium silicate. The structural information of the calcium silicate‐cellulose composites are derived by both theoretical and experimental techniques. Low‐energy ground state geometrical structures of the cellulose on the triclinic wollastonite surfaces and their interactions have been primarily determined by Density Functional Theory. Accordingly, the short‐range structural information is confirmed by Pair Distribution Function analysis. Structural information along with binding interactions are also confirmed from X‐ray photoelectron spectroscopy. The implications of these detailed analysis of structures in tuning the properties of such ceramic polymeric hybrid composites for futuristic endodontic application is discussed.

The conventional crystallographic structure solution by X-ray Diffraction technique using Rietveld method prove its great potential for determination of the average structure of the materials for long range periodicity. Experimentally, the structural information of long range periodic atomic ordering of material is reflected in the Bragg's peaks while local or short range structure is reflected in the diffuse peaks. In order to obtain structural information about both average and local atomic structures, need a technique that will consider both Braggs peaks as well as diffuse peaks. Therefore, Total Scattering Atomic Pair Distribution Function (PDF) technique based on Debye Scattering function will be the only possible solution. At present synchrotron and neutron sources are the choice for PDF analysis for short range structure study. But there is a need for routine analysis of such type of samples in a conventional laboratory XRD system to get the quick feedback about the short range structure. PDF analysis can be performed in a Laboratory X-ray diffractometer using Ag radiation (λ = 0.5608 Å) to obtain maximum Q value i.e. 22 Å-1. The present work will report PDF based methodology in a laboratory XRD system to extract structural information about nanostructured and disordered materials over short and long range for structural characterization of crystalline and amorphous materials. Present work will report how this PDF technique used to unravel the structure of disordered materials and nanomaterials like amorphous silica, Ni, nano Ba-based Perovskite, etc for better understanding the materials at nano level. Structural information as obtained by the PDF analysis will help to control the performance of the disordered materials for tailoring the materials at nano scale. This method may be applicable to the characterization of the nanoscale crystalline and amorphous materials based on PDF analysis in Laboratory XRD system using Ag Radiation. This proposed experimental technique will help to quick feedback about local or disordered structure based on PDF using Ag radiation in a laboratory XRD system.

Barium titanate (BT) is extensively used in electronic industries for its high dielectric constant. However, the dielectric properties of BT significantly change due to carbonation at nanoscale. Commercially available tetragonal BT powder was milled to study the local atomic distribution and phase transformation behaviour with temperature. Nano BT powder was prepared by the high energy ball milling (90 h) from its bulk counterpart. It was carbonated when it was exposed to open atmosphere. The milled BT sample was characterised by high temperature X-ray diffraction (HT-XRD), pair distribution function (PDF) and transmission electron microscope (TEM). Local atomic distribution was obtained from PDF analysis. The peak due to CO and Ba-C pair distance were observed from PDF for 90 h milled carbonated BT. TEM analysis revealed that particle diameter was in the range of 15-50 nm. How the phase of nano BT ceramics transformed with temperature was strudied. It was observed that orthorhombic BT transformed into tetragonal and cubic phase via the monoclinic phase during heating at 900°C. Coexistence of multi phases of BT was also observed from HT-XRD. BaCO 3 disappeared at high temperature.

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