Synthesis crystallographic characterization and electrical properties of titania and zirconia based ceramic materials

Table of Contents

CHAPTER- 1

Introduction and Survey of Literature

1.1 Definition

1.2 Structure and properties of ceramic materials

1.3 Advanced ceramics and their applications

1.4 Scope of the present work

1.5 Survey of relevant literature

Substituted sodium zirconium phosphate (NZP)

Substituted perovskites

Substituted calcium titanate

Substituted barium titanate

Substituted zirconolites

CHAPTER- 2

Instrumental Techniques and Structure refinement

2.1 X-ray Diffraction method

2.2 Structure Determination

2.3 Software applications in solving structures

2.3.1 Indexing programs

2.3.2 GSAS - Rietveld refinement

2.4 Scanning Electron Microscopy (SEM)

2.5 Energy Dispersive X-ray microanalysis (EDAX)

2.6 Impedance Spectroscopy

2.7 Infrared Spectroscopy

2.8 Magic Angle Spinning NMR

CHAPTER-3

Experimental procedures and data

3.1 Methods of synthesis and materials characterization

3.2 Characterization of ceramic phases

3.2.1 XRD: Phase analysis and Rietveld refinement

3.2.2 SEM/EDAX: Grain size, morphology and elemental analysis

3.3 Impedance Study: Electrical behavior

3.3.1 Dielectric measurements

3.4 Infrared Spectroscopy

3.5 MAS-NMR Spectroscopy

3.6 Experimental data

CHAPTER-4

Results and Discussion

4.1 Substituted Sodium Zirconium Phosphates (NZP)

4.1.1 Antimony substituted sodium zirconium phosphate: Na1+xZr2-xSbxP3O12 (where x=0.05-0.2)

4.1.2 Aluminum/ Chromium substituted sodium zirconium phosphate: Na1+xZr2-x (Al/Cr)xP3O12 (where x=0.1)

4.1.3 Molybdenum substituted sodium zirconium phosphate: Na1-xZr2(PO4)3-x(MoO4)x (where x=0.1& 0.15)

4.1.4 NZP ceramic waste forms

TYPE-I:Na1.49Zr1.56Sn0.02Fe0.28Cr0.07Ni0.07P3O12

TYPE-II:Na1.35Ba0.14Zr1.56Sn0.02Fe0.28Cr0.07Ni0.07P2.86Si0.14O12

0-35wt% WOx loaded waste forms

4.2 Perovskites

4.2.1 Calcium Yttrium Titanate: Ca1-xYxTiO3 (where x=0.1- 0.3)

4.2.2 Calcium Iron Niobium Titanate: CaTi1-x(Fe0.5Nb0.5)xO3 (x=0.1- 0.1.0)

4.2.3 Substituted Barium Titanate: BaTi1-(x+y)ZrxMnyO3 (0≤x<0.1, 0.01

4.3 Zirconolite

4.3.1 Substituted Calcium zirconium Titanate: Ca1-xMxZrTi2O7 (M=Y, La and x=0.1)

Research Objectives and Topics

The primary research objective of this work is the synthesis, crystallographic characterization, and electrical property analysis of titania and zirconia-based ceramic materials to evaluate their potential as matrix materials for the management of radioactive waste.

• Investigation of structure-property relationships in substituted ceramic phases.
• Application of Rietveld refinement for structural analysis of powder X-ray diffraction data.
• Study of the electrical properties and dielectric behavior of ceramic materials for sensor and insulating applications.
• Development of synthetic routes for ceramic waste forms to improve resistance to environmental leaching.
• Analysis of structural distortions and atomic coordination using spectroscopic and microscopic techniques.

Excerpt from the Book

Summary of Chapters

CHAPTER- 1 Introduction and Survey of Literature: Provides a comprehensive definition of ceramics, an overview of their structural and physical properties, and a literature survey on relevant ceramic families like NZP and Perovskites.

CHAPTER- 2 Instrumental Techniques and Structure refinement: Details the scientific methodologies used, including X-ray diffraction, structural refinement via GSAS, microscopy, and spectroscopic techniques like NMR and Impedance analysis.

CHAPTER-3 Experimental procedures and data: Outlines the systematic synthetic routes used to prepare ceramic precursors and the specific experimental data sets obtained for characterization.

CHAPTER-4 Results and Discussion: Analyzes the experimental findings, focusing on the structural analysis, bond distortions, and electrical properties of synthesized Substituted Sodium Zirconium Phosphates, Perovskites, and Zirconolites.

Keywords

Ceramics, Radioactive Waste, Zirconolite, Perovskites, NZP, Rietveld refinement, X-ray diffraction, Impedance spectroscopy, SEM, EDAX, MAS-NMR, Dielectric constant, Solid state reaction, Ionic substitution, Structural analysis.

Frequently Asked Questions

What is the primary scope of this research?

The work focuses on the synthesis and characterization of ceramic materials (titania and zirconia-based) to assess their suitability as durable waste forms for the immobilization of high-level nuclear waste.

Which materials are primarily investigated in this study?

The study investigates three main groups of materials: Sodium zirconium phosphates (NZP), Perovskites, and Zirconolites.

What is the primary scientific goal regarding structural analysis?

The goal is to understand the structural complexity and atomistic interactions within these ceramic precursors using powder X-ray diffraction data and Rietveld refinement techniques.

Which analytical methods were employed for characterization?

The research employed a range of techniques including X-ray Diffraction (XRD), Scanning Electron Microscopy (SEM), Energy Dispersive X-ray Analysis (EDAX), Impedance Spectroscopy, Infrared (IR) Spectroscopy, and Magic Angle Spinning Nuclear Magnetic Resonance (MAS-NMR).

What is the significance of the electrical property investigation?

Electrical investigations were conducted to explore potential applications in electronic materials, insulators, and sensor technologies, specifically looking at how structural substitutions affect dielectric behavior.

Which parameters are typically derived from the Rietveld refinement?

Refinement provides lattice parameters, atomic positions, site occupancies, interatomic distances, and thermal parameters, which help in verifying the stability and phase purity of the synthesized materials.

How does the substitution of rare earth elements affect Zirconolite?

Substitution of elements like Nd or Yb in Zirconolite influences the formation of different polytypes (e.g., 3T, 2M) depending on the level of substitution and synthesis temperature, which is critical for waste encapsulation.

Why are perovskites like Calcium Titanate significant?

Perovskites are identified as key components for synthetic rock (synroc) precursors because they can accommodate a wide range of radionuclides in their lattice structure through flexible chemical doping.