Phase transition and melting pressures of solid ethane

Abstract
The melting pressures of ethane at 14 temperatures from near the triple point to 95.50 K and pressures to 32.0 MPa are reported. A triple point temperature of 90.348±0.005 K is obtained from the data which is in agreement with the determination of Clusius and Weigand (1940) but in substantial disagreement with other determinations. Qualitative evidence has been obtained which indicates the existence of a previously unrecognized solid phase transition along a boundary roughly parallel to the melting line at a temperature about 0.5 K below the melting temperature, suggesting that some previous melting point determinations may have been influenced by a misinterpretation of the effects of this transition.