Solids are of immense technological importance

Close-Packed Structures

The most efficient way to fill space with spheres?


Other materials can be considered to form in similar structures to metals

Buckminsterfullerene






ALL Compounds are Solids under suitable conditions of temperature and pressure. Many exist only as solids.

Solids (especially Crystals) are of immense technological importance, they have always been fascinating.

Mechanical Properties

# Metals/Alloys, e.g. Titanium for aircraft
# Cement/Concrete Ca3SiO5
# 'Ceramics', e.g. clays, BN, SiC
# Lubricants, e.g. Graphite, MoS2
# Abrasives, e.g. Diamond

Electrical Properties

* Metallic Conductors, e.g. Cu, Ag...
* Semiconductors, e.g. Si, GaAs
* Superconductors, e.g. Nb3Sn, YBa2Cu3O7
* Electrolytes, e.g. LiI in pacemaker batteries
* Piezoelectrics, e.g. a Quartz (SiO2) in watches


Magnetic Properties

* e.g. CrO2, Fe3O4 for recording technology


Optical Properties

* Pigments, e.g. TiO2 in paints
* Phosphors, e.g. Eu3+ in Y2O3 is red on TV
* Lasers, e.g. Cr3+ in Al2O3 is ruby
* Frequency-doubling of light, e.g. LiNbO3

Catalysts

* Zeolite ZSM-5 (an aluminosilicate)

o - Petroleum refining
o - methanol octane

Sensors

* Oxygen sensor, e.g. ZrO2/CaO solid solution



Some Basic Definitions

LATTICE = An infinite array of points in space, in which each point has identical surroundings to all others.

CRYSTAL STRUCTURE = The periodic arrangement of atoms in the crystal.

It can be described by associating with each lattice point a group of atoms called the MOTIF (BASIS)




http://www.chem.ox.ac.uk/icl/heyes/introtosolids/sumsch.html