Answer to Question #134991 in Inorganic Chemistry for NISAA

Question

Zinc sulphide (ZnS) has two common polymorphs which is sphalerite and wurtzite.
i. Diffrentiate the arrangement of ions in the sphalerite and wurtzite structure.
ii. By using your own illustration, briefly explain two most common atom orientations that generate close-packed lattice.

Answer 1

. Zinc sulfide (ZnS) is a unique compound that forms two types of crystalline structures. These two polymorphs are wurtzite and zincblende (also known as sphalerite). Wurtzite has a hexagonal structure, while zincblende is cubic.

Ii. ZnS has a unique structure type compared to other molecules, having different types of unique structures. ZnS can have a zinc blende structure which is a "diamond-type network" and at a different temperature, ZnS can become the wurtzite structure type which has a hexagonal type symmetry. Structure-wise, the zinc blende structure is more thermodynamically favored, however, because of the wurtzite structures slow construction, both forms of ZnS can be found.