Cadmium arsenide

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Cadmium arsenide
Cadmium arsenide crystals.jpg
Cd3As2 crystals with (112) and (400) orientations [1]
Cadmium arsenide STM2.jpg
STM image of the (112) surface [1]
Names
Other names
Tricadmium diarsenide
Identifiers
3D model (JSmol)
ChemSpider
ECHA InfoCard 100.031.336 OOjs UI icon edit-ltr-progressive.svg
EC Number
  • 234-484-1
PubChem CID
  • InChI=1/2As.3Cd/q2*-3;3*+2
    Key: PYIKGNIRLAMTQG-UHFFFAOYAS
  • [Cd+2].[Cd+2].[Cd+2].[AsH6-3].[AsH6-3]
Properties
Cd3As2
Molar mass 487.08 g/mol
Appearancesolid, dark grey
Density 3.031
Melting point 716 °C (1,321 °F; 989 K)
decomposes in water
Structure [2]
Tetragonal, tI208
I41/acd, No. 142-2
a = 1.26512(3) nm, c = 2.54435(4) nm
Hazards
GHS labelling:
GHS-pictogram-skull.svg GHS-pictogram-exclam.svg GHS-pictogram-silhouette.svg GHS-pictogram-pollu.svg
Danger
H301, H312, H330, H350, H410
P201, P202, P260, P261, P264, P270, P271, P273, P280, P281, P284, P301+P310, P302+P352, P304+P340, P308+P313, P310, P311, P312, P320, P321, P322, P330, P363, P391, P403+P233, P405, P501
NFPA 704 (fire diamond)
NFPA 704.svgHealth 4: Very short exposure could cause death or major residual injury. E.g. VX gasFlammability 1: Must be pre-heated before ignition can occur. Flash point over 93 °C (200 °F). E.g. canola oilInstability 0: Normally stable, even under fire exposure conditions, and is not reactive with water. E.g. liquid nitrogenSpecial hazard W: Reacts with water in an unusual or dangerous manner. E.g. sodium, sulfuric acid
4
1
0
W
Lethal dose or concentration (LD, LC):
no data
NIOSH (US health exposure limits):
PEL (Permissible)
[1910.1027] TWA 0.005 mg/m3 (as Cd) [3]
REL (Recommended)
Ca [3]
IDLH (Immediate danger)
Ca [9 mg/m3 (as Cd)] [3]
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).

Cadmium arsenide (Cd 3 As 2) is an inorganic semimetal in the II-V family. It exhibits the Nernst effect.

Contents

Properties

Thermal

Cd3As2 dissociates between 220 and 280 °C according to the reaction [4]

2 Cd3As2(s) → 6 Cd(g) + As4(g)

An energy barrier was found for the nonstoichiometric vaporization of arsenic due to the irregularity of the partial pressures with temperature. The range of the energy gap is from 0.5 to 0.6 eV. Cd3As2 melts at 716 °C and changes phase at 615 °C/ [5]

Phase transition

Pure cadmium arsenide undergoes several phase transitions at high temperatures, making phases labeled α (stable), α’, α” (metastable), and β. [6] At 593° the polymorphic transition α → β occurs.

α-Cd3As2 ↔ α’-Cd3As2 occurs at ~500 K.
α’-Cd3As2 ↔ α’’-Cd3As2 occurs at ~742 K and is a regular first order phase transition with marked hysteresis loop.
α”-Cd3As2 ↔ β-Cd3As2 occurs at 868 K.

Single crystal x-ray diffraction was used to determine the lattice parameters of Cd3As2 between 23 and 700 °C. Transition α → α′ occurs slowly and therefore is most likely an intermediate phase. Transition α′ → α″ occurs much faster than α → α′ and has very small thermal hysteresis. This transition results in a change in the fourfold axis of the tetragonal cell, causing crystal twinning. The width of the loop is independent of the rate of heating although it becomes narrower after several temperature cycles. [7]

Electronic

The compound cadmium arsenide has a lower vapor pressure (0.8 atm) than both cadmium and arsenic separately. Cadmium arsenide does not decompose when it is vaporized and re-condensed. Carrier Concentration in Cd3As2 are usually (1–4)×1018 electrons/cm3. Despite having high carrier concentrations, the electron mobilities are also very high (up to 10,000 cm2/(V·s) at room temperature). [8]

In 2014 Cd3As2 was shown to be a semimetal material analogous to graphene that exists in a 3D form that should be much easier to shape into electronic devices. [9] [10] Three-dimensional (3D) topological Dirac semimetals (TDSs) are bulk analogues of graphene that also exhibit non-trivial topology in its electronic structure that shares similarities with topological insulators. Moreover, a TDS can potentially be driven into other exotic phases (such as Weyl semimetals, axion insulators and topological superconductors), Angle-resolved photoemission spectroscopy revealed a pair of 3D Dirac fermions in Cd3As2. Compared with other 3D TDSs, for example, β-cristobalite BiO
2 and Na3Bi, Cd3As2 is stable and has much higher Fermi velocities. In situ doping was used to tune its Fermi energy. [10]

Conducting

Cadmium arsenide is a II-V semiconductor showing degenerate n-type semiconductor intrinsic conductivity with a large mobility, low effective mass and highly non parabolic conduction band, or a Narrow-gap semiconductor. It displays an inverted band structure, and the optical energy gap, eg, is less than 0. When deposited by thermal evaporation (deposition), cadmium arsenide displayed the Schottky (thermionic emission) and Poole–Frenkel effect at high electric fields. [11]

Magnetoresistance

Cadmium Arsenide shows very strong quantum oscillations in resistance even at the relatively high temperature of 100K. [12] This makes it useful for testing cryomagnetic systems as the presence of such a strong signal is a clear indicator of function.

Preparation

Schematic of the vapor growth of Cd3As2 crystals using an alumina furnace. Cadmium arsenide growth.png
Schematic of the vapor growth of Cd3As2 crystals using an alumina furnace.

Cadmium arsenide can be prepared as amorphous semiconductive glass. According to Hiscocks and Elliot, [5] the preparation of cadmium arsenide was made from cadmium metal, which had a purity of 6 N from Kock-Light Laboratories Limited. Hoboken supplied β-arsenic with a purity of 99.999%. Stoichiometric proportions of the elements cadmium and arsenic were heated together. Separation was difficult and lengthy due to the ingots sticking to the silica and breaking. Liquid encapsulated Stockbarger growth was created. Crystals are pulled from volatile melts in liquid encapsulation. The melt is covered by a layer of inert liquid, usually B2O3, and an inert gas pressure greater than the equilibrium vapor pressure is applied. This eliminates the evaporation from the melt which allows seeding and pulling to occur through the B2O3 layer.

Crystal structure

The unit cell of Cd3As2 is tetragonal. [2] [13] The arsenic ions are cubic close packed and the cadmium ions are tetrahedrally coordinated. The vacant tetrahedral sites provoked research by von Stackelberg and Paulus (1935), who determined the primary structure. Each arsenic ion is surrounded by cadmium ions at six of the eight corners of a distorted cube and the two vacant sites were at the diagonals. [2]

The crystalline structure of cadmium arsenide is very similar to that of zinc phosphide (Zn3P2), zinc arsenide (Zn3As2) and cadmium phosphide (Cd3P2). These compounds of the Zn-Cd-P-As quaternary system exhibit full continuous solid-solution. [14]

Nernst effect

Cadmium arsenide is used in infrared detectors using the Nernst effect, and in thin-film dynamic pressure sensors. It can be also used to make magnetoresistors, and in photodetectors. [15]

Cadmium arsenide can be used as a dopant for HgCdTe.

Related Research Articles

<span class="mw-page-title-main">Band gap</span> Energy range in a solid where no electron states exist

In solid-state physics and solid-state chemistry, a band gap, also called a bandgap or energy gap, is an energy range in a solid where no electronic states exist. In graphs of the electronic band structure of solids, the band gap refers to the energy difference between the top of the valence band and the bottom of the conduction band in insulators and semiconductors. It is the energy required to promote an electron from the valence band to the conduction band. The resulting conduction-band electron are free to move within the crystal lattice and serve as charge carriers to conduct electric current. It is closely related to the HOMO/LUMO gap in chemistry. If the valence band is completely full and the conduction band is completely empty, then electrons cannot move within the solid because there are no available states. If the electrons are not free to move within the crystal lattice, then there is no generated current due to no net charge carrier mobility. However, if some electrons transfer from the valence band to the conduction band, then current can flow. Therefore, the band gap is a major factor determining the electrical conductivity of a solid. Substances having large band gaps are generally insulators, those with small band gaps are semiconductor, and conductors either have very small band gaps or none, because the valence and conduction bands overlap to form a continuous band.

<span class="mw-page-title-main">Epitaxy</span> Crystal growth process relative to the substrate

Epitaxy refers to a type of crystal growth or material deposition in which new crystalline layers are formed with one or more well-defined orientations with respect to the crystalline seed layer. The deposited crystalline film is called an epitaxial film or epitaxial layer. The relative orientation(s) of the epitaxial layer to the seed layer is defined in terms of the orientation of the crystal lattice of each material. For most epitaxial growths, the new layer is usually crystalline and each crystallographic domain of the overlayer must have a well-defined orientation relative to the substrate crystal structure. Epitaxy can involve single-crystal structures, although grain-to-grain epitaxy has been observed in granular films. For most technological applications, single-domain epitaxy, which is the growth of an overlayer crystal with one well-defined orientation with respect to the substrate crystal, is preferred. Epitaxy can also play an important role while growing superlattice structures.

<span class="mw-page-title-main">Semimetal</span>

A semimetal is a material with a very small overlap between the bottom of the conduction band and the top of the valence band. According to electronic band theory, solids can be classified as insulators, semiconductors, semimetals, or metals. In insulators and semiconductors the filled valence band is separated from an empty conduction band by a band gap. For insulators, the magnitude of the band gap is larger than that of a semiconductor. Because of the slight overlap between the conduction and valence bands, semimetals have no band gap and a negligible density of states at the Fermi level. A metal, by contrast, has an appreciable density of states at the Fermi level because the conduction band is partially filled.

A superlattice is a periodic structure of layers of two materials. Typically, the thickness of one layer is several nanometers. It can also refer to a lower-dimensional structure such as an array of quantum dots or quantum wells.

In chemistry, an arsenide is a compound of arsenic with a less electronegative element or elements. Many metals form binary compounds containing arsenic, and these are called arsenides. They exist with many stoichiometries, and in this respect arsenides are similar to phosphides.

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Zinc arsenide (Zn3As2) is a binary compound of zinc with arsenic which forms gray tetragonal crystals. It is an inorganic semiconductor with a band gap of 1.0 eV.

<span class="mw-page-title-main">Topological insulator</span> State of matter with insulating bulk but conductive boundary

A topological insulator is a material whose interior behaves as an electrical insulator while its surface behaves as an electrical conductor, meaning that electrons can only move along the surface of the material.

Bismuth selenide is a gray compound of bismuth and selenium also known as bismuth(III) selenide.

In materials science, the term single-layer materials or 2D materials refers to crystalline solids consisting of a single layer of atoms. These materials are promising for some applications but remain the focus of research. Single-layer materials derived from single elements generally carry the -ene suffix in their names, e.g. graphene. Single-layer materials that are compounds of two or more elements have -ane or -ide suffixes. 2D materials can generally be categorized as either 2D allotropes of various elements or as compounds.

<span class="mw-page-title-main">Molybdenum ditelluride</span> Chemical compound

Molybdenum(IV) telluride, molybdenum ditelluride or just molybdenum telluride is a compound of molybdenum and tellurium with formula MoTe2, corresponding to a mass percentage of 27.32% molybdenum and 72.68% tellurium.

<span class="mw-page-title-main">Weyl semimetal</span> Concept in quantum physics

Weyl fermions are massless chiral fermions embodying the mathematical concept of a Weyl spinor. Weyl spinors in turn play an important role in quantum field theory and the Standard Model, where they are a building block for fermions in quantum field theory. Weyl spinors are a solution to the Dirac equation derived by Hermann Weyl, called the Weyl equation. For example, one-half of a charged Dirac fermion of a definite chirality is a Weyl fermion.

Bismuth antimonides, Bismuth-antimonys, or Bismuth-antimony alloys, (Bi1−xSbx) are binary alloys of bismuth and antimony in various ratios.

<span class="mw-page-title-main">Dirac cone</span> Quantum effect in some non-metals

In physics, Dirac cones are features that occur in some electronic band structures that describe unusual electron transport properties of materials like graphene and topological insulators. In these materials, at energies near the Fermi level, the valence band and conduction band take the shape of the upper and lower halves of a conical surface, meeting at what are called Dirac points.

The term Dirac matter refers to a class of condensed matter systems which can be effectively described by the Dirac equation. Even though the Dirac equation itself was formulated for fermions, the quasi-particles present within Dirac matter can be of any statistics. As a consequence, Dirac matter can be distinguished in fermionic, bosonic or anyonic Dirac matter. Prominent examples of Dirac matter are graphene and other Dirac semimetals, topological insulators, Weyl semimetals, various high-temperature superconductors with -wave pairing and liquid helium-3. The effective theory of such systems is classified by a specific choice of the Dirac mass, the Dirac velocity, the gamma matrices and the space-time curvature. The universal treatment of the class of Dirac matter in terms of an effective theory leads to a common features with respect to the density of states, the heat capacity and impurity scattering.

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Zinc cadmium phosphide arsenide (Zn-Cd-P-As) is a quaternary system of group II (IUPAC group 12) and group V (IUPAC group 15) elements. Many of the inorganic compounds in the system are II-V semiconductor materials. The quaternary system of II3V2 compounds, (Zn1−xCdx)3(P1−yAsy)2, has been shown to allow solid solution continuously over the whole compositional range. This material system and its subsets have applications in electronics, optoelectronics, including photovoltaics, and thermoelectrics.

<span class="mw-page-title-main">Bismuth compounds</span>

Bismuth compounds are compounds containing the element bismuth (Bi). Bismuth forms trivalent and pentavalent compounds, the trivalent ones being more common. Many of its chemical properties are similar to those of arsenic and antimony, although they are less toxic than derivatives of those lighter elements.

<span class="mw-page-title-main">Tantalum arsenide</span> Chemical compound

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References

  1. 1 2 3 Sankar, R.; Neupane, M.; Xu, S.-Y.; Butler, C. J.; Zeljkovic, I.; Panneer Muthuselvam, I.; Huang, F.-T.; Guo, S.-T.; Karna, Sunil K.; Chu, M.-W.; Lee, W. L.; Lin, M.-T.; Jayavel, R.; Madhavan, V.; Hasan, M. Z.; Chou, F. C. (2015). "Large single crystal growth, transport property, and spectroscopic characterizations of three-dimensional Dirac semimetal Cd3As2". Scientific Reports. 5: 12966. Bibcode:2015NatSR...512966S. doi:10.1038/srep12966. PMC   4642520 . PMID   26272041.
  2. 1 2 3 Ali, M. N.; Gibson, Q.; Jeon, S.; Zhou, B. B.; Yazdani, A.; Cava, R. J. (2014). "The Crystal and Electronic Structures of Cd3As2, the Three-Dimensional Electronic Analogue of Graphene". Inorganic Chemistry. 53 (8): 4062–4067. arXiv: 1312.7576 . doi:10.1021/ic403163d. PMID   24679042.
  3. 1 2 3 NIOSH Pocket Guide to Chemical Hazards. "#0087". National Institute for Occupational Safety and Health (NIOSH).
  4. ↑ Westmore, J. B.; Mann, K. H.; Tickner, A. W. (1964). "Mass Spectrometric Study of the Nonstoichiometric Vaporization of Cadmium Arsenide1". The Journal of Physical Chemistry. 68 (3): 606–612. doi:10.1021/j100785a028.
  5. 1 2 Hiscocks, S. E. R.; Elliott, C. T. (1969). "On the preparation, growth and properties of Cd3As2". Journal of Materials Science. 4 (9): 784–788. Bibcode:1969JMatS...4..784H. doi:10.1007/BF00551073. S2CID   136483003.
  6. ↑ Pietraszko, A.; Łukaszewicz, K. (1969). "A refinement of the crystal structure of α"-Cd3As2". Acta Crystallographica Section B. 25 (5): 988–990. doi:10.1107/S0567740869003323.
  7. ↑ Pietraszko, A.; Łukaszewicz, K. (1973). "Thermal expansion and phase transitions of Cd3As2 and Zn3As2". Physica Status Solidi A. 18 (2): 723–730. Bibcode:1973PSSAR..18..723P. doi:10.1002/pssa.2210180234.
  8. ↑ Dowgiałło-Plenkiewicz, B.; Plenkiewicz, P. (1979). "Inverted band structure of Cd3As2". Physica Status Solidi B. 94 (1): K57–K60. Bibcode:1979PSSBR..94...57D. doi:10.1002/pssb.2220940153.
  9. ↑ Neupane, M.; Xu, S. Y.; Sankar, R.; Alidoust, N.; Bian, G.; Liu, C.; Belopolski, I.; Chang, T. R.; Jeng, H. T.; Lin, H.; Bansil, A.; Chou, F.; Hasan, M. Z. (2014). "Observation of a three-dimensional topological Dirac semimetal phase in high-mobility Cd3As2". Nature Communications. 5: 3786. arXiv: 1309.7892 . Bibcode:2014NatCo...5.3786N. doi:10.1038/ncomms4786. PMID   24807399.
  10. 1 2 Liu, Z. K.; Jiang, J.; Zhou, B.; Wang, Z. J.; Zhang, Y.; Weng, H. M.; Prabhakaran, D.; Mo, S. K.; Peng, H.; Dudin, P.; Kim, T.; Hoesch, M.; Fang, Z.; Dai, X.; Shen, Z. X.; Feng, D. L.; Hussain, Z.; Chen, Y. L. (2014). "A stable three-dimensional topological Dirac semimetal Cd3As2". Nature Materials. 13 (7): 677–81. Bibcode:2014NatMa..13..677L. doi:10.1038/nmat3990. PMID   24859642.
  11. ↑ Din, M.; Gould, R. D. (2006). "Van der Pauw resistivity measurements on evaporated thin films of cadmium arsenide, Cd3As2". Applied Surface Science. 252 (15): 5508–5511. Bibcode:2006ApSS..252.5508D. doi:10.1016/j.apsusc.2005.12.151.
  12. ↑ Narayanan, A.; Watson, M. D.; Blake, S. F.; Bruyant, N.; Drigo, L.; Chen, Y. L.; Prabhakaran, D.; Yan, B.; Felser, C.; Kong, T.; Canfield, P. C.; Coldea, A. I. (19 March 2015). "Linear Magnetoresistance Caused by Mobility Fluctuations in -Doped". Physical Review Letters. 114 (11): 117201. arXiv: 1412.4105 . doi:10.1103/PhysRevLett.114.117201. PMID   25839304. S2CID   35607875.
  13. ↑ Kim, H.; Goyal, M.; Salmani-Rezaie, S.; Schumann, T.; Pardue, T. N.; Zuo, J-M.; Stemmer, S. (2019). "Point group symmetry of cadmium arsenide thin films determined by convergent beam electron diffraction". Physical Review Materials. 3: 084202. arXiv: 1908.05734 . doi: 10.1103/PhysRevMaterials.3.084202 .
  14. ↑ Trukhan, V. M.; Izotov, A. D.; Shoukavaya, T. V. (2014). "Compounds and solid solutions of the Zn-Cd-P-As system in semiconductor electronics". Inorganic Materials. 50 (9): 868–873. doi:10.1134/S0020168514090143. S2CID   94409384.
  15. ↑ Din, M.B.; Gould, R.D. (1998). "High field conduction mechanism of the evaporated cadmium arsenide thin films". ICSE'98. 1998 IEEE International Conference on Semiconductor Electronics. Proceedings (Cat. No.98EX187). p. 168. doi:10.1109/SMELEC.1998.781173. ISBN   0-7803-4971-7. S2CID   110904915.
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