Cadmium phosphide (
Cd3 P2) is an
inorganic
In chemistry, an inorganic compound is typically a chemical compound that lacks carbon–hydrogen bonds, that is, a compound that is not an organic compound. The study of inorganic compounds is a subfield of chemistry known as ''inorganic chemist ...
chemical compound
A chemical compound is a chemical substance composed of many identical molecules (or molecular entities) containing atoms from more than one chemical element held together by chemical bonds. A molecule consisting of atoms of only one element ...
. It is a grey or white bluish solid
semiconductor material
A semiconductor is a material which has an electrical conductivity value falling between that of a conductor, such as copper, and an insulator, such as glass. Its resistivity falls as its temperature rises; metals behave in the opposite way. ...
with a bandgap of 0.5 eV.
It has applications as a pesticide, material for laser diodes and for high-power-high-frequency electronics.
Synthesis and reactions
Cadmium phosphide can be prepared by the reaction of
cadmium
Cadmium is a chemical element with the symbol Cd and atomic number 48. This soft, silvery-white metal is chemically similar to the two other stable metals in group 12, zinc and mercury. Like zinc, it demonstrates oxidation state +2 in most of ...
with
phosphorus
Phosphorus is a chemical element with the symbol P and atomic number 15. Elemental phosphorus exists in two major forms, white phosphorus and red phosphorus, but because it is highly reactive, phosphorus is never found as a free element on Ear ...
:
:6 Cd + P
4 → 2 Cd
3P
2
Structure
Cd
3P
2 has a room-temperature
tetragonal
In crystallography, the tetragonal crystal system is one of the 7 crystal systems. Tetragonal crystal lattices result from stretching a cubic lattice along one of its lattice vectors, so that the cube becomes a rectangular prism with a squar ...
form.
The crystalline structure of cadmium phosphide is very similar to that of
zinc phosphide (Zn3P2),
cadmium arsenide (Cd3As2) and
zinc arsenide (Zn3As2). These compounds of the
Zn-Cd-P-As quaternary system exhibit full continuous solid-solution.
Applications
Safety
Like other metal phosphides, it is acutely toxic when swallowed due to the formation of
phosphine
Phosphine (IUPAC name: phosphane) is a colorless, flammable, highly toxic compound with the chemical formula , classed as a pnictogen hydride. Pure phosphine is odorless, but technical grade samples have a highly unpleasant odor like rotting ...
gas when it reacts with
gastric acid. It is also carcinogen and dangerous for the skin, eyes and other organs in a large part due to
cadmium poisoning
Cadmium is a naturally occurring toxic metal with common exposure in industrial workplaces, plant soils, and from smoking. Due to its low permissible exposure in humans, overexposure may occur even in situations where trace quantities of cadmium ...
.
References
{{Phosphorus compounds
Phosphides
phosphide
In chemistry, a phosphide is a compound containing the ion or its equivalent. Many different phosphides are known, with widely differing structures. Most commonly encountered on the binary phosphides, i.e. those materials consisting only of phos ...
II-V semiconductors
II-V compounds