Cadmium arsenide

Cadmium arsenide (Cd3As2) is an inorganic semimetal in the II-V family. It exhibits the Nernst effect. Cadmium arsenide (Cd3As2) is an inorganic semimetal in the II-V family. It exhibits the Nernst effect. Cd3As2 dissociates between 220 and 280 °C according to the reaction 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/ Pure cadmium arsenide undergoes several phase transitions at high temperatures, making phases labeled α (stable), α’, α” (metastable), and β. At 593° the polymorphic transition α → β occurs. 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. 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). 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. 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 BiO2 and Na3Bi, Cd3As2 is stable and has much higher Fermi velocities. In situ doping was used to tune its Fermi energy. 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. Cadmium Arsenide shows very strong quantum oscillations in resistance even at the relatively high temperature of 100K.. This makes it useful for testing cryomagnetic systems as the presence of such a strong signal is a clear indicator of function