What is the crystal structure of ZnS?
What is the crystal structure of ZnS?
Zinc sulphide exists with two different crystal structures, the cubic zinc blend (top diagram) and the hexagonal Wurtzite (lower diagram). In the zinc blend structure the sulphur ions form an fcc structure and the zinc ions occupy half of the tetrahedral sites in this structure to attain charge neutrality.
What Bravais lattice is ZnS?
The Bravais lattice of ZnS is a face-centred cube. The crystal structure of ZnS is considered as the interpenetration of two FCC sub-lattices along the body diagonal such that the origin of one sub-lattice is at a distance of 1/4th the body diagonal from the origin along the body diagonal.
Is ZnS BCC or fcc?
Zincblende/sphalerite is based on a fcc lattice of anions whereas wurtzite is derived from an hcp array of anions. In both structures, the cations occupy one of the two types of tetrahedral holes present.
Which set of characteristics of ZnS crystal is correct?
ZnS has ccp structure (fee) in which S2− ions occupy comers and face-centres and Zn2+ ions are present in alternate tetrahedral voids. Further, each Zn2+ ion is surrounded tetrahedrally by 4S2− ions and vice-versa.
What type of unit cell is ZnS?
2. What type of unit cell is ZnS? Zinc sulfide (ZnS) is a unique compound that forms two types of crystalline structures. Zinc Sulphide is an ionic compound of AB type, i.e it contains two ions of ratio 1:1.
What type of cell is ZnS?
|Zincblende Vital Statistics|
|Space Group||F4(bar)3m, No.???|
|Cell Parameters||a = 5.41 Å, Z=4|
|Atomic Positions||S: 0, 0, 0 Zn: 0.25, 0.25, 0.25 (can interchange if desired)|
Which is are correct statement about zinc blende structure?
The structure of the zinc blende (Sphalerite) is based on a face-centered cubic structure whereas the structure of Wurtzite is hexagonal cubic centered. In both the structures there are 2 types of tetrahedral holes, in which half of them are occupied by the cations.
Which of the following is not correct about is ZnS structure?
We should know that in zinc blende structure (ZnS), sulphide ions are face-centred and zinc is present in alternate tetrahedral voids. Formula is ZnS. Coordination number of Zn is 4 and that of sulphide is 4. So, from this we can say that this statement is incorrect.
What is ZnS used for?
The most common use of ZnS is as a pigment for paints, plastics, and rubber. Lithopone, a mixture of ZnS and barium sulfate (BaSO4), is a widely used pigment for low-gloss paints. ZnS is phosphorescent, which makes it useful for several electronic and decorative applications.
Which one of the following statements is wrong about zinc blende ZnS type structure?
How many tetrahedral holes are in ZnS?
– Like ZnS in diamond Carbon occupies half of the tetrahedral voids or holes. – The total number of tetrahedral voids in fcc is 8. – Out of 8 voids, carbon occupies half of it means four. – Therefore the percentage of occupancy of the tetrahedral void by carbon in the diamond is 50%.
What is the basis of ZnS?
What is the Colour of ZnS?
Colour of zinc sulphide is white.
Why is ZnS white?
As the size of the cation increases, upon moving down in the periodic table, the overlap between the orbitals decreases and the band gap shifts to lower energy. Since, the band gap decreases from ZnS to HgS, the colour of ZnS is white, CdS is yellow and HgS is black.
Is ZnS aqueous or solid?
Zinc sulfide appears as a yellowish-white powder in a liquid. Insoluble in water and denser than water.
What is the bonding type of ZnS?
The chemical structure of ZnS is simple and consists of the zinc metal attached to a sulfur atom through a polar covalent bond.
What are the 7 crystal systems?
• There are seven unique arrangements ,known as crystal systems, which fill in a three dimensional space. 16. THE 7 CRYSTAL SYSTEMS 1. Cubic Crystals a = b= c = = = 90º Fluorite Octahedron Pyrite Cube 17. 2. Tetragonal Crystals a = b c = = = 90º Zircon 18. 3. Orthorhombic Crystals a b c = = = 90º Topaz 19. 4.
How do we obtain a crystal structure?
7. -so we obtain a crystal structure by adding the lattice and basis – So we can say that, When an atom or identical group of atoms is attached to every lattice point, we obtain a crystal structure. 8. • Crystals are classified into two types 1.
How many octahedral sites are present in NaCl?
STRUCTURE TYPES 2. Rock Salt (NaCl) • Fcc with respect to anions. • Cations occupy octahedral voids. • Octahedral sites are present at edge centres and body centre. • There are 4 octahedral sites per unit cell. • General formula AX. • CN of anion=8 • CN of cation=8 3. • Each ion and its neighbours can be represented by apt. polyhedra.
Where are the lattice points located in a cubic crystal system?
– Lattice points are located at the corner of the unit cell and in some cases, at either faces or the centre of the unit cell. 11. • Here for the cubic crystal system we have Simple cubic (SC), Face-centred cubic (FCC),and Body-centred cubic (BCC). 12. Total no. of atom per simple cubic cell is 8 (1/8) = 1 atom