Tantalum(IV) sulfide
Encyclopedia
Tantalum sulfide is the inorganic compound
with the formula Ta
S2
. It is a layered compound with three-coordinate sulfide centres and trigonal prismatic metal centres. It is structurally similar to the more famous material MoS2. TaS2 is a semiconductor with d1 electron configuration.
Although an obscure material otherwise, TaS2 has been the subject of many studies because it is a versatile host for intercalation
of electron donors.
TaS2 is prepared by the high temperature reaction of powdered tantalum and sulfur. It is purified and crystallized by chemical vapor transport using iodine
as the transporting agent:
The crystallographic structure of tantalum disulfide shows a number of complexities. One of its forms 1T-TaS2 undergoes a number of phase transitions as a function of temperature. In the lowest temperature phase, the commensurate phase (below 180K) there is a commensurate superstructure, known as a charge density wave (CDW), at an angle of 13.9 degrees relative to the lattice. In a incommensurate phase above 353K the wave is aligned with the lattice. Two more structures exist: a nearly commensurate one appears between 353K and 180K upon cooling. Upon warming a triclinic phase is first formed between 223K and 283K to revert to the nearly commensurate one at 283K. Both these phases have different superstructures.
Inorganic compound
Inorganic compounds have traditionally been considered to be of inanimate, non-biological origin. In contrast, organic compounds have an explicit biological origin. However, over the past century, the classification of inorganic vs organic compounds has become less important to scientists,...
with the formula Ta
Tantalum
Tantalum is a chemical element with the symbol Ta and atomic number 73. Previously known as tantalium, the name comes from Tantalus, a character in Greek mythology. Tantalum is a rare, hard, blue-gray, lustrous transition metal that is highly corrosion resistant. It is part of the refractory...
S2
Sulfide
A sulfide is an anion of sulfur in its lowest oxidation state of 2-. Sulfide is also a slightly archaic term for thioethers, a common type of organosulfur compound that are well known for their bad odors.- Properties :...
. It is a layered compound with three-coordinate sulfide centres and trigonal prismatic metal centres. It is structurally similar to the more famous material MoS2. TaS2 is a semiconductor with d1 electron configuration.
Although an obscure material otherwise, TaS2 has been the subject of many studies because it is a versatile host for intercalation
Intercalation (chemistry)
In chemistry, intercalation is the reversible inclusion of a molecule between two other molecules . Examples include DNA intercalation and graphite intercalation compounds.- DNA intercalation :...
of electron donors.
TaS2 is prepared by the high temperature reaction of powdered tantalum and sulfur. It is purified and crystallized by chemical vapor transport using iodine
Iodine
Iodine is a chemical element with the symbol I and atomic number 53. The name is pronounced , , or . The name is from the , meaning violet or purple, due to the color of elemental iodine vapor....
as the transporting agent:
- TaS2 + 2 I2
TaI4 + 2 S
The crystallographic structure of tantalum disulfide shows a number of complexities. One of its forms 1T-TaS2 undergoes a number of phase transitions as a function of temperature. In the lowest temperature phase, the commensurate phase (below 180K) there is a commensurate superstructure, known as a charge density wave (CDW), at an angle of 13.9 degrees relative to the lattice. In a incommensurate phase above 353K the wave is aligned with the lattice. Two more structures exist: a nearly commensurate one appears between 353K and 180K upon cooling. Upon warming a triclinic phase is first formed between 223K and 283K to revert to the nearly commensurate one at 283K. Both these phases have different superstructures.