NIOBIUM: PROPERTIES, PRODUCTION AND APPLICATIONS -- NIOBIUM: PROPERTIES, PRODUCTION AND APPLICATIONS -- CONTENTS -- PREFACE -- Chapter 1 THE ROLE OF NIOBIUM SPECIES IN HETEROGENEOUS CATALYSIS - SELECTED ASPECTS -- Abstract -- 1. Introduction -- 2. Heterogeneous Catalysis - General Remarks -- 3. Niobium Species in Catalysts Applied for Heterogeneous Oxidation Processes -- 3.1. Gas phase oxidative dehydrogenation (ODH) of propane -- 3.1.1 General information about the catalytic process -- 3.1.2 Role of Niobium in ODH of Propane -- 3.2 Gas Phase Ammoxidation of Propane -- 3.2.1 General Information about the Catalytic Process -- 3.2.2 Role of Niobium in Ammoxidation of Propane -- 3.3. Gas Phase Oxidation of Methanol -- 3.3.1. General Information about the Catalytic Process -- 3.3.2. Role of Niobium in Methanol Oxidation Process -- 3.4. Liquid Phase Epoxidation of Olefins -- 3.4.1. General Information about the Catalytic Process -- 3.4.2 Role of Niobium in Epoxidation of Olefins -- 3.5 Liquid Phase Oxidation and Ammoxidation of Glycerol -- 3.5.1 General information about the Catalytic Process -- 3.5.1 Role of Niobium in Oxidation and Ammoxidation of Glycerol -- 4. Final remarks -- Acknowledgments -- References -- Chapter 2 STUDIES ON NOVEL SOLID ACID CATALYSTS OF NIOBIUM-BASED OXIDES WITH MESOPOROUS, LAYERED AND NANOSHEET STRUCTURES -- Abstract -- 1. Introduction -- 2. Nanosheets and Layered Metal Oxide as Solid Acid Catalysts -- 2.1 Exfoliated nanosheets -- 2.1.1 Structures of Aggregated Nanosheets -- 2.1.2. Acid Properties of Exfoliated Niobium Oxide Nanosheets -- NH3-TPD -- 1H MAS NMR -- 31P MAS NMR -- 2.1.3. Acid Catalytic Activity -- 2.2. Layered HNbMoO6 -- 2.2.1 Structures of Layered HNbMoO6 -- 2.2.2. Acid Properties of Layered HNbMoO6 -- 31P MAS NMR -- 2.2.3. Acid Catalytic Activity -- 2.3. Biorefinery Applications -- 2.4. Conclusion.

3. Mesoporous Metal Oxides as Solid Acid Catalyst -- 3.1 Mesoporous Nb2O5·nH2O Oxides -- 3.2 Mesoporous Nb Sulfated Oxides -- 3.3 Nb-incorporated Mesoporous Silicas -- 3.4 Mesoporous NbxW(10-x) Oxides -- Structures of Mesoporous NbxW(10-x) Oxides -- Acid Properties of Mesoporous Metal Oxides -- FT-IR -- 31P MAS NMR -- Acid Catalytic Activity -- 3.5 Conclusion -- References -- Chapter 3 NIOBIUM OXIDE COMPOUNDS: SYNTHESIS, PROPERTIES AND APPLICATIONS -- Abstract -- Introduction -- PART A - Ocurrence, Structures and Physicochemical Properties -- Niobium Oxides and it's Physicochemical Properties -- Niobium Pentoxide an it'S Polymorphism -- PART B - Synthetic Strategies -- Direct Solid-State Reaction Synthesis -- Conventional and Homogeneous Solution Precipitation -- Coprecipitation Methods -- Hydrothermal -- Sol-Gel Processing -- Microemulsion Technique -- Templated/Surface Derivatized Nanoparticles -- Conclusion -- References -- Chapter 4 GEOCHEMISTRY OF NB AND VARIATIONS OF NB/TA RATIO IN GEOLOGICAL SYSTEMS -- Abstract -- 1. Introduction -- 2. Geochemistry of Niobium -- 3. Relation of Niobium and Tantalum -- 3.1 Fractionation of Nb and Ta by Scheelite and Rutile from Metaturbidite-hosted Quartz Vein Gold Deposits -- 3.2 Fractionation of Nb and Ta in Peraluminous Granitic Pluton -- Conclusion -- References -- Chapter 5 DENSIFICATION OF IN SITU CU-NBC COMPOSITE USING UNIAXIAL AND COLD ISOSTATIC PRESSING -- Abstract -- 1.0 Introduction -- 2.0 Experimental Work -- 3.0 Results and Discussion -- 3.1 Characterization of As-milled Powder -- 3.1.1 X-ray Diffraction Analysis -- 3.1.2 Microstructure Observation -- 3.2 Characterization of Sintered Cu-NbC Composite -- 3.2.1 X-ray Diffraction Analysis -- 3.2.2 Bulk Properties of Sintered Composite -- Conclusion -- Acknowledgments -- References.

Chapter 6 NIOBIUM POWDERS: USES AND PROCESS DEVELOPMENTS FOR THEIR PRODUCTION -- Abstract -- Introduction -- Production of Niobium Powders -- Hunter Process -- Reduction of Niobium Oxides by Magnesium -- Electrochemical Processes -- Reduction of Niobium Oxides by Silicon -- Further metallothermic reduction methods -- Reduction of Niobium Chloride by Hydrogen -- Deoxidation of Niobium Powders -- Production of Derivatives -- Usage of Niobium Powders -- Electrolytic Capacitors -- Superconductors -- Further Areas of Application -- Conclusion -- References -- Chapter 7 IMPROVEMENT OF THE ELECTROCHEMICAL BEHAVIOR OF AISI 4140 STEEL SUBSTRATE USING [TICN/TINBCN]N MULTILAYERS SYSTEM -- Abstract -- 1. Introduction -- 2. Experimental Details -- 3. Results and Discussion -- 3.1 Multilayered Structural and Chemical Characterization -- 3.2. Scanning Electron Microscopy Analysis -- 3.3 Electrochemical Impedance Spectroscopy (EIS) and Tafel polarization curves of [TiCN/TiNbCN]n multilayered coatings -- Summary -- Acknowledgments -- References -- Chapter 8 NIOBIUM DISTRIBUTION PATTERN IN RARE-METAL-BEARING PALAEOPROTEROZOIC CO-GENETIC FELSIC ROCKS AND MINERALS IN CENTRAL INDIA -- Abstract -- Introduction -- Geological Settings -- Evolutionary Trend of the Investigated Co-genetic Granite-Pegmatite System -- Methods of Investigation -- Niobium Distribution Pattern -- References -- Chapter 9 NIOBIUM IN OXALATE COMPLEXES: FROM DISCRETE MOLECULES TO HETEROMETALLIC SUPRAMOLECULAR STRUCTURES -- Abstract -- Introduction -- Bis(oxalato)Oxoniobates(V) -- Tris(oxalato)oxoniobates(V) -- Oxalatoniobates(V) in Extended Structures -- Oxalatoniobates(V) in Complexes with Homo- and Heterometallic Dinuclear Units -- Oxalate Complexes with Niobium in Lower Oxidation States -- Conclusion -- References.

Chapter 10 A NOVEL AMPEROMETRIC TRANSDUCER ELECTRODE WITH IRIDIUM-NIOBIUM BINARY ALLOYS -- 1. Introduction -- 2. Experimental -- 3. Results and discussion -- Acknowledgments -- Conclusion -- References -- Chapter 11 NIOBATE CRYSTALS INSERTED IN A GLASS MATRIX -- ABSTRACT -- 1. INTRODUCTION -- 1.1. State of-the-Art -- 1.1.a. Lithium Niobate (LiNbO3) Crystal -- 1.1.b. LiNbO3 Glasses -- 2. EXPERIMENTAL METHODS -- 2.1. Sample Preparation -- 2.2. Glass-Ceramics -- 2.2.a. Thermal treatments (TT) -- 2.2.b. Thermoelectric treatments (TTE) -- 2.3. Structural characterization thecniques -- 2.3.a. X-ray diffraction (XRD) -- 2.3.b. Scanning Electron Microscopy (SEM) -- 2.3.c. Raman spectroscopy -- 2.3.d. Electric and dielectric spectroscopy -- 3. RESULTS -- 3.1. Results of the 60sio2-30Li2O-10Nb2O5 (% Mole) Composition -- Sample Appearance -- XRD, Raman and SEM -- Electric and Dielectric Measurements -- 3.2. 44sio2-33Li2O-23Nb2O5 (% Mole) Composition -- Sample Appearance -- XRD, Raman and SEM -- Electric and Dielectric Measurements -- 3.3. 34sio2-33Li2O-33Nb2O5 (%Mole) Composition -- Sample Appearance -- XRD, Raman And SEM -- Electric and Dielectric Measurements -- 4. ANALYSIS -- CONCLUSIONS -- REFERENCES -- ANNEX -- Chapter 12 USE OF NIOBIUM FOR FABRICATING SUPERCONDUCTING RADIO FREQUENCY CAVITIES* -- Abstract -- 1. Introduction -- Section 1. Some Fundamental Parameters Employed in SRF Technology -- 1.1. Quality Factor Qo -- 1.2. Accelerating Gradient Eacc -- 1.3. Surface Resistance Rs -- RRR Value -- Section 2.Why is Nb the Material of Choice -- Section 3. Fabrication of Nb Cavities -- 3.1. Typical Fabrication Steps for a Nb SRF Cavity -- 3.2. Examples of Innovative Techniques for Fabricating Nb SRF Cavities -- 3.3. Examples of New Developments in Inspection Technique -- 3.3.1. Eddy Current And SQUID Scanning -- 3.3.2. Kyoto Camera.

3.3.3. Replica Technique -- 3.4. Examples of New Developments in Final Chemical Treatment -- 3.4.1. Buffered Electropolishing (BEP) -- 3.4.2. Other New Developments to Remove Nb -- 3.5. Examples of New Developments in Final Cleaning Technique -- 3.5.1. GCIB Technique -- 3.5.2. DIC Technique -- Section 4. Requirements in Physical, Chemical, Metallurgical, Mechanical Properties of Nb for Fabricating High Quality SRF Cavities -- 4.1. Requirements in Physical Properties -- 4.1.1. Surface Oxide Layer Structure -- 4.1.2. High Field Q-Slope -- 4.1.3. Surface Smoothness -- 4.2. Requirements in Chemical Properties -- 4.2.1. Q Disease -- 4.2.2. Effect of Impurity Concentration on Thermal Conductivity -- 4.3. Requirements in Metallurgical Properties -- 4.4. Requirements in Mechanical Properties -- Section 5. Summary and Perspective -- References -- Chapter 13 INVESTIGATION OF SURFACE TREATMENTS OF NIOBIUM FLAT SAMPLES AND SRF CAVITIES BY GAS CLUSTER ION BEAM TECHNIQUE FOR PARTICLE ACCELERATORS* -- Abstract -- 1. Introduction -- 2. Brief History of GCIB and Its Application to Nb -- 3. Working Principal of GCIB -- 4. Suppression of Field Emission by GCIB Treatments -- 5. Modifications of Morphology of Nb Surfaces by GCIB -- 6. Modifications of Surface Oxide Layer Structure by GCIB -- 7. GCIB Treatments on Nb Single Cell Cavities -- 8. Summary and Perspective -- Acknowledgment -- References -- Chapter 14 ELECTRODEPOSITION OF NIOBIUM FROM MOLTEN SALTS* -- Abstract -- Introduction -- Experimental -- Electrolytic Cell -- Electrolytic Solution -- Niobium Electrorefining -- Preliminary Investigation -- Influence of Cathodic Current Density -- Influence of Temperature -- Influence of K2NbF7 Concentration -- Electroplating - Electroforming -- Influence of Anode/Cathode Distance and Cathode Shape -- Corrosion Resistance of Niobium Electroplates.

Electroformed Articles.