The velocity of sound and compressibility in the melts of Hg-Te system

Liquid Hg-Te system has been investigated as a function of composition and temperature by measuring the velocity of sound. A minimum in the sound velocity as a function of temperature observed for Te persists up to 50 at.% Hg, of which the position increases rather steeply between 20 and 30 at.% Hg. This suggests that the molten HgTe and alloys in the Te-rich side undergo structural changes involving the change in coordination number with increasing temperature, and the crossover of the nature of the chemical bond from p-p to sp³ covalent bond takes place with changing composition. It is concluded that the structural change in liquid HgTe is due to intrinsic nature of bonding of HgTe as a compound. Received 2 September 1998 and Received in final form 16 March 1999