Chapter 7 Electrical properties

Typical values of electrical conductivity

Formation of polyacetylene and polyethylene

Polyparaphenylene and polypyrrole

TCNQ, TTF,…

Electrical resistance of YBa 2 Cu 3 O 7

Meissner effect showing repulsion of a superconductor

Levitation inaction

Type I and II superconductors

Some superconducting materials

Perovskite-related cuperate structures showing octahedral YBa 2 Cu 3 O 6 YBa 2 Cu 3 O 7 BaTiO 3 Rb x WO 3 ABO 3 A 3 B 3 O 9-2 A 3 B 3 O 9-3 Cu 2+ Cu + Cu 2+ Cu 3+ Y Ba

Perovskite-related cuperate structures showing square planar

Cu +3, d 8 ; Cu +2, d 9 ; and Cu(I), d 10 s 1

Crystal structures of YBa 2 Cu 3 O 7 and YBa 2 Cu 3 O 6

T c vs oxygen content YBa 2 Cu 3 O  YBa 2 Cu 3 O  Pressure of O 2 in bars Oxygen loss on heating

T c as a function of lattice parameter for K 3 C 60 more metallicless metallic The interaction of C anions determines conductivity.

Conductivity of metals, semiconductors and insulators

Relation between electronic properties and magnitude of the band gap

p-type semiconductivity in gallium-doped silicon

n-type semiconductivity in arsenic-doped silicon

A pn junction

Migration of cation vacancies

Schematic ionic conductivity of doped NaCl crystal E m = activation energy of cation migration E f = activation energy to form Schottky defects  = ne  0 exp(-E m /RT) n = N exp(-E f /2RT) Low temp High temp Na 1-2x Mn x V x Cl

Pathway for Na + migration in NaCl

Triangular interstice

Ionic conductivity of pure NaCl as a function of temperature

Conductivity in NaCl crystals

Migration of interstitial Ag + ions by direct interstitial jump and indirect interstitialcy mechanism

Effect of Cd +2 on conductivity of AgCl crystals  depends on [Ag i + ] Addition of Cd 2+ decreases [Ag i + ] first, then increase [V Ag ]. This indicates more than one mechanisms for conductivity.

Solid electrolytes as intermediate between normal crystalline solids and liquids

Ionic conductivity of some solid electrolytes LT HT

Oxide layers in  -alumina

Oxide packing in  - and  ’’-alumina

Conduction plane in  -alumina

Conductivity of PbF 2 An example of F - anionic conductor

Some oxide ion conductors

Electrochemical cell containing a solid electrolyte

Components of a secondary lithium battery

A thin film electrochromic device

Oxygen concentration cell

Dielectric material between two plates of a parallel plate capacitor

Hysteresis loop of a ferroelectric

Some ferroelectric materials

Spontaneous polarization of a TiO 6 octahedron in BaTiO 3

Dipole orientation in a ferroelectric, an antiferroelectric, and a ferrielectric

Ferroelectric domains separated by a domain wall or boundary

Dielectric constant for barium titanate ceramic paraelectricantiferroelectric  ‘= C/(T-  ) Curie-Weiss Law

Antiferroelectric-ferroelectric transition in PbZrO 3 as a function of applied field antiferroelectric ferroelectric

Displacement of phosphorus within a PO 2 (OH) 2