Define the following terms "
(i) n-type semiconductor.
(ii) Ferrimagnetism.

Explanation

(i) n-type semiconductor : When group 14 elemetns like Silicon (Si) or Germanium (Ge) are doped with group 15 element like P or As, one electron will be free and get delocalised which increases the conductivity of Si or Ge. Hence, the Silicon or Germanium crystals doped with electron rich impurities are called n-type semiconductors.
(ii) Ferrimagnetism : It arises due to the unequal number of domains in opposite direction resulting in some net magnetic moment. For example : Magnetite `(Fe_(3)O_(4))`.