Chapter 7Chapter 7

Electrical properties

Typical values of electrical conductivity

Formation of polyacetylene and polyethylene

Polyparaphenylene and polypyrrole

TCNQ, TTF,…

Electrical resistance of YBa2Cu3O7

Meissner effect showing repulsion of a superconductor

Levitation inaction

Type I and II superconductors

Some superconducting materials

Perovskite-related cuperate structures showing octahedral

YBa2Cu3O6

YBa2Cu3O7

BaTiO3RbxWO3

ABO3

A3B3O9-2

A3B3O9-3

Cu2+

Cu+

Cu2+

Cu3+

Y

Ba

Perovskite-related cuperate structures showing square planar

Cu+3, d8; Cu+2, d9; and Cu(I), d10s1

Crystal structures of YBa2Cu3O7 and YBa2Cu3O6

Tc vs oxygen content

YBa2Cu3O

YBa2Cu3O

Pressure of O2 in bars

Oxygen loss on heating

Tc as a function of lattice parameter for K3C60

more metallic less metallic

The interaction of C603- 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

Em = activation energy of cation migrationEf = activation energy to form Schottky defects

= ne0exp(-Em/RT)

n = N exp(-Ef/2RT)

Low tempHigh temp

Na1-2xMnxVxCl

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[Agi

+]

Addition of Cd2+ decreases [Agi+] first, then increase [VAg].

This indicates more than one mechanisms for conductivity.

Solid electrolytes as intermediate between normal crystalline solids and liquids

Ionic conductivity of some solid electrolytes

LTHT

Oxide layers in -alumina

Oxide packing in - and ’’-alumina

Conduction plane in -alumina

Conductivity of PbF2

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 TiO6 octahedron in BaTiO3

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 PbZrO3 as a function of applied field

antiferroelectric

ferroelectric

Displacement of phosphorus within a PO2(OH)2