| Popis: |
The new phase PtPb2 was prepared at high pressure (7.7 GPa) and temperature (1300–1500 K). Determination of the structure showed that it had the CuAl2-type structure (space group I4/mcm, Z = 4) with tetragonal unit cell parameters a = 6.934 ± 0.003 A , c = 5.764 ± 0.003 A . The heat of decomposition H and the activation energy of this process E were measured at normal pressure: H = 8.7±0.6 kJ mol−1, E = 108±7 kJ mol−1. The new phase transformed into the superconducting state at T = 3 ± 0.2 K. The band structure, density of states and volume, the dependence of the total energy of the new phase were calculated using the LMTO method. |
