Triple point on the melting curve and polymorphism of nitrogen at high pressure.

摘要: Raman spectra of solid and fluid nitrogen to pressures up 120 GPa temperatures 2500 K reveal that the melting line exhibits a maximum near 70 GPa, followed by triple point 87 after which temperature rises again. Fluid remains molecular over entire pressure range studied, there is no sign fluid-fluid transition. Solid phases obtained on quenching from melt above 48 are identical recently discovered $\ensuremath{\iota}$ ${\ensuremath{\zeta}}^{\ensuremath{'}}$ phases. We find kinetics plays major role in experimentally observed phase changes account for metastability various crystalline existence an amorphous single bonded $\ensuremath{\eta}\ensuremath{-}\mathrm{N}$.