Introduction to functional ceramic materials. Structure, properties, preparation and applications Vincenzo Buscaglia Istituto per l’Energetica e le Interfasi Consiglio Nazionale delle Ricerche Via De Marini 6, 16149 Genoa [email protected] What a ceramic is ? From Greek word “keramos” (pottery, potter’s clay) Inorganic nonmetallic materials obtained by the action of heat and subsequent cooling Polycrystalline materials, single phase or multiphase (composites), sometimes with an amorphous component (glass) Traditional ceramics •Whitewares: tableware, cookware, sanitary ware, etc. •Refractories (kiln and furnace linings for steel and glass industry) •Structural clay products (floor & roof tiles, bricks, etc.) Fabricated from clay, quartz, feldspar (earthenware) and kaolin (porcelain) Technical/advanced ceramics •Structural ceramics (mechanical properties: strength, toughness, hardness, creep resistance) •Functional ceramics (electric, magnetic, optical properties) Structural ceramics Two Kyocera ceramic knives (Y:ZrO2) Ceramic body armour plates (Al2O3, SiC) The Porsche Carrera GT's silicon carbide disk brake Ceramic Si3N4 bearing parts Radial rotor made from Si3N4 for a gas turbine engine Functional ceramics Functionality Material Applications Resistors SiC, MoSi2, LaCrO3 Heating elements for high temperature furnaces Thermistors (NTCR & PTCR) Spinels BaTiO3 Temperature sensors, self-regulating heating elements Dielectrics with very low losses (r = 3 -10) Al2O3, AlN, cordierite Substrates for electronic circuits and chip packaging Dielectrics for microwave applications (r = 30-80) BaTi4O9, Zr(Ti,Sn)O4, BaMg1/3Ta2/3O3, (Ba,Sr)TiO3, MW resonators, filters and antennas for mobile communications and GPS devices, tunable MW devices Temperature stable dielectrics (r 100) CaTiO3, BaONd2O3-TiO2 Capacitors with temperatureindependent capacitance Dielectrics with very high dielectric constant (r 3000) BaTiO3 Multilayer ceramic capacitors Piezoelectric ceramics Pb(Zr,Ti)O3 (PZT) Transducers, actuators and resonators Pyroelectric ceramics Pb(Zr,Ti)O3 IR radiation detection and imaging Functional ceramics Functionality Material Applications Ferroelectric ceramics Pb(Zr,Ti)O3 SrBi2Ta2O9 Ferroelectric memories (FeRAMs) Electrostrictive ceramics PbMg1/3Nb2/3O3 -PbTiO3 (PMN-PT) Actuators Magnetic ceramics Spinels (Ni,Zn)Fe2O4 BaFe12O19 Y3Fe5O12 (YIG) Inductors Permanent magnets Microwave devices (radars) Ionic conductors Y:ZrO2 (YSZ) Gd:CeO2 β-alumina Electrolytes for solid-oxide fuel cells (SOFCs), oxygen sensors Na-Batteries Superconductors YBa2Cu3O7-x (YBCO) MgB2 Superconducting cables for magnets Transparent ceramics Al2O3, MgAl2O4, Y3Al5O12 (YAG) Phosphors, optical materials for lenses and laser systems, nose cones for heatseeking missiles, high-pressure sodium street lamps Optoelectronic materials LiNbO3 PLZT Waveguides, frequency doublers, voltage-controlled optical switches, modulators Thick (left) and thin (right) substrates (alumina) Pressed and extruded parts (alumina, mullite, zirconia) Ferrites cores Microwave dielectric components Low Temperature Co-fired Ceramics (LTCC) Ceramic Multilayer Substrates Monolithic Multilayer Ceramic Capacitors (modified BaTiO3) Pyroelectric Infrared sensor (PZT) SAW filter (SIO2, LiNbO3, LiTaO3) Ceramic resonators (SiO2, PZT, BaMg1/3Ta2/3O3) Thermistors (NTCR: spinels; PTCR: modified BaTiO3) Ceramic filters (BaMg1/3Ta2/3O3, Zr(Sn,Ti)O4) Cheap ferrite beads (hexaferrites BaFe12O19) Multilayer piezoelectric ceramic actuators for diesel injection system (PZT – PbZrxTi1-xO3) Multilayer technology used for higher performances and device miniaturization Multilayer ceramic capacitors: most widely used ceramic components in ME Microstructure of ceramics Glossary: grains, grain boundaries, pores, secondary phases, domain walls, relative density, grain size, grain size distribution, texture, etc. Fully dense 99% Al2O3, transparent Partially porous 99% Al2O3, transparent Liquid-phase sintered 96% Al2O3 with secondary glassy phase Further details: Classification&Microstructure.ppt Outlook of the course Introduction. Why a course on functional ceramics? (Introduction.ppt) Processing of ceramic materials: forming and sintering (Processing.ppt). Structure and properties of grain boundaries. Nanoceramics (GrainBoundaries.ppt). Ceramics for electronics: ferroelectric and piezoelectric ceramics, dielectrics with high dielectric constants (BaTiO3, PbZrxTi1-xO3, (K,Na)NbO3) (Ferroelectrics.ppt, Piezoelectrics.ppt) -Multilayer ceramic capacitors. Miniaturization of devices and related issues. -Piezoelectric actuators and transducers. -Lead-free materials. Multiferroic materials (BiFeO3, magnetoelectric composites): a challenge for materials science. (Multiferroics.ppt) Ceramics for energy: (SOFC.ppt, MIEC.ppt) -Ionic and mixed high-temperature conductors (Y:ZrO2, Gd:CeO2, (La,Sr)MnO3) -Solid-oxide fuel cells. -Ceramic membranes for gas separation. Required background General background in physics, chemistry and materials science. Knowledge of most common crystal structures (fluorite, spinel, perovskite). Perovskites.ppt Defects and defect chemistry in oxides, extended defects, doping, p- and n- type semicondutors, defect chemistry and electrical conductivity. Defects.ppt Electric and dielectric properties of crystalline solids: polarization, complex dielectric permittivity, ac dielectric properties, impedance, dielectric relaxation. Dielectrics.ppt Fundamentals of solid-state magnetism Suggested readings Books A.J. Moulson & J.M. Herbert, Electroceramics, Chapman & Hall. W.D. Kingery, H.K. Bowen, D.R. Uhlmann, Introduction to Ceramics, John Wiley & Sons. Review papers F. Ernst, O. Kienzle and M. Rühle, Structure and Composition of Grain Boundaries in Ceramics, J. Europ. Ceram. Soc. 19,665-673 (1999). S. von Alfthan et al., The Structure of Grain Boundaries in Strontium Titanate: Theory, Simulation and Electron Microscopy, Annu. Rev. Mater. Res. 40,557–99 (2010). G. H. Haertling, Ferroelectric Ceramics: History and Technology, J. Am. Ceram. Soc. 82,797–818 (1999). D. Damjanovic, Ferroelectric, dielectric and piezoelectric properties of ferroelectric thin films and ceramics, Rep. Prog. Phys. 61,1267–1324 (1998). L. Jin, F. Li, S. Zhang, Decoding the Fingerprint of Ferroelectric Loops: Comprehension of the Material Properties and Structures, J. Am. Ceram. Soc. 97,1–27 (2014) A.K. Tagantsev et al., Ferroelectric Materials for Microwave Tunable Applications, J. Electroceramics 11, 5–66 (2003). S. Zhang & F. Li, High performance ferroelectric relaxor-PbTiO3 single crystals: Status and perspective, J. Appl. Phys. 111,031301 (2012). J. Rodel et al., Perspective on the Development of Lead-free Piezoceramics, J. Am. Ceram. Soc. 92, 1153-1177 (2009) T. R. Shrout & S. J. Zhang, Lead-free piezoelectric ceramics: Alternatives for PZT?, J. Electroceram. 19,111–124 (2007) C.A. Randall et al., High Strain Piezoelectric Multilayer Actuators—A Material Science and Engineering Challenge, J. Electroceramics 14,177-191 (2005). M. Fiebig, Revival of the Magnetoelectric Effect, J. Phys. D.: Appl. Phys. 38,R123-R152 (2005) C.A.F. Vaz et al., Magnetoelectric Coupling Effects in Multiferroic Complex Oxide Composite Structures, Adv. Mat. 22,2900-2918 (2010). J. van den Brink, D. I. Khomskii, Multiferroicity due to charge ordering, J. Phys.: Condens. Matter 20,434217 (2008) M. Winter & M.J. Brodd, What Are Batteries, Fuel Cells, and Supercapacitors?, Chem. Rev. 104,42454269 (2004). A. J. Jacobson, Materials for Solid Oxide Fuel Cells, Chem. Mater. 22,660-674 (2010). A. Orera & P. R. Slater, New Chemical Systems for Solid Oxide Fuel Cells, Chem. Mater. 22,675-690 (2010). J. Sunarso et al., Mixed ionic–electronic conducting (MIEC) ceramic-based membranes for oxygen separation, J. Membrane Science 320,13–41 (2008) S. Baumann et al., Manufacturing strategies for asymmetric ceramic membranes for efficient separation of oxygen from air, J. Europ. Ceram. Soc. 33,1251-1261 (2013). A. Feteira, Negative Temperature Coefficient Resistance (NTCR) Ceramic Thermistors: An Industrial Perspective, J. Am. Ceram. Soc., 92, 967–983 (2009). W. Wersing, Microwave ceramics for resonators and filters, Current Opinion in Solid State & Materials Science 1,715-731 (1996.) I. Reaney & D. Iddles, Microwave Dielectric Ceramics for Resonators and Filters in Mobile Phone Networks, J. Am. Ceram. Soc. 89,2063–2072 (2006).