Question

List the three factors that you should consider when trying to predict the crystal structure for a ceramic material. In one to two sentences or bullets explain why each is important.

Answer 1

The three factors that should consider predicting the crystal structure for a ceramic material is its stronger bond, ionic radii and chemical inertness.

o Ceramic material contains metal cations, which are positively charged and anion which are negatively charge.

o The ratio of ionic radii (r cation /r anion ) predict the coordination number of anions around each

cation.

o - As the ratio gets larger the coordination number gets larger and larger.

o The strength of an ionic bond depends on the size of the charge on each ion and on the radius of each ion.

o There is the greater the force of attraction, because the greater the number of electrons is shared.

o Due to these types of bonds, ceramic material has high elastic modulus and hardness, high melting points, low thermal expansion, and good chemical resistance.