Computer estimation of the CdHgTe phase diagram (original) (raw)

The compounds CdHgTe and its constituent binaries CdTe, HgTe, and CdHg are semiconductors which are used in thermal, infrared, nuclear, thermoelectric and other photo sensitive devices. The compo~d CdHgTe has a Sphaleritic structure of possible type AilB:ICI1. The TERCP program of Kaufman is used to estimate the stable regions of the ternary phase diagram using available thermodynamic data. It was found that there was little variation in stochiometry with temperature. The compositions were calculated for temperatures ranging from 325K to IOOK and the compositional limits were Cd13_20Hg12_01Te75_79, Hg varying most. By comparison with a similar compound, Cd In2Te4 of forbidden band width .88 to .90 e.v., similar properties are postulated for CdlHglTe6 with applications in the infra red region of the spectrum at 300K where this composition is given by TERCP at the limit of stability. Pressure ,p Free energy for the system A ,AFA Temperature ,'I' Free energy in TERCP ,Gi Van Laars Parameters,eo e 1 e2 ep x,y,z ternary coordination Interaction parameter for the liquid phase ,L concentration in field phi ,x' Interaction parameter for the BCC phase ,B concentration in field psi, xy Enthalpy of formation ,AHf