MSE-

ceramics are materials and nonmetallic compounds for which interatomic bonds are ionic or predominantly ionic with covalent bonds.

ceramics differ from metals in their properties in that they have a more complex crystal structure, have higher melting points, and aren’t electrical conductors

-high melting point

-hard & brittle as a result of ionic and covalent compounds

-AX (rock salt)

-AX2 (fluorite)

-ABX3 (perovskite)

-AB2X4 (spinel)

an anion is a negatively charged ion, a cation is a positively charged ion

a coordination # is the number of anion nearest neighbors to cation

• frenkel (cation-vacancy x cation interstital)

• schottky (cation vacancy x anion vacancy)

• silica is the simplest material made up of silicon and oxygen

• silicate is salts containing both silicon and oxygen

• sand

• clay

• zirconia

chain double bonds
(ii) bulky side groups
(iii) polar groups.
(iv) molecular weights

ceramics are made up of ionic and covalent bonds which are highly directional & do not easily slip. these bond types have limited slip systems and reduce dislocation making ceramica harder to deform and cause brittleness.

metals on the other hand, are made up of metallic bonds and which have significantly more slip systems and are therefore easier to deform

glass transition temp is where upon cooling, a noncrystalline ceramic or polymer transforms from a supercooled liquid to rigid glass

melting point on the other hand is where upon heating a material phase transforms into a liquid

a polymer is a chain like structure made up of repeating unit monomers. these monomers form a repeating long macromolecular chain, during polymerization reactive monomer sites, extend the chain

• linear: repeat units are joined together end to end in single chains

• branched: structure w/ side-branched chains extending from primary chains

• cross-linked: adjacent linear chains joined together by covalent bonds

• network: multifunctional monomers w/ 3+ active covalent bonds; creates 3D networks

thermoplastics soften when heated and harden when cooled while thermosetting polymers are permanently hard and do not soften with heating

Large elastic extensions are possible for elastomeric materials that are amorphous and lightly
crosslinked. Deformation corresponds to the unkinking and uncoiling of chains in response to an
applied tensile stress. Crosslinking is often achieved during a vulcanization process; increased
crosslinking enhances the modulus of elasticity and the tensile strength of the elastomer. Many
elastomers are copolymers, whereas silicone elastomers are really inorganic materials

• molecular weight = increases as tensile strength increases

• degree crystallinity = tensile modulus increases significantly as crystallinity increases

• pre deformation= Stiffness and strength are enhanced by permanently deforming the polymer in tension

• heat treatment = tensile modulus increases as annealing temp increases

• the ease with which a material transmits an electric current

• electrical resistivity = (measure of material’s resistance to the passage of electric current) is related to resistance (how much the material used to make wire/component resists current) bc resistivity depends on resistance (the amount of current passing through a wire or lack thereof is inherently related to what the wire was made with)

• molecular weight

• chemical bonds

• degree crystallinity

• chain stiffness

SEE TXTBOOK

• Metals are good conductors, typically having conductivities on the order of 107 (Ω·m)−1. electrical insulators are materials with very low conductivities, ranging between 10−10 and 10−20 (Ω·m)−1;. Materials with intermediate conductivities, generally from 10−6 to
  104 (Ω·m)−1, are termed semiconductors.

In the band structure of electrons, one band is completely filled with electrons. If an empty conduction band exits separated from the valence band, an energy gap lies
between them

• For intrinsic behavior, the electrical properties are inherent in the pure material, and electron
  and hole concentrations are equal.

• extrinsic = Electrical behavior is dictated by impurities for extrinsic semiconductors. Extrinsic
  semiconductors may be either n- or p-type depending on whether electrons or holes,
  respectively, are the predominant charge carriers

…

• Ferroelectric materials exhibit spontaneous polarization

• electric field is generated when mechanical stresses are applied to a piezoelectric material.