Low Temperature Physics: 39, 427 (2013); https://doi.org/10.1063/1.4807044 (3 pages)
Физика Низких Температур: Том 39, Выпуск 5 (Май 2013), c. 552-555    ( к оглавлению , назад )

Melting line of polymeric nitrogen

L.N. Yakub

Thermophysics Department, Odessa State Academy of Refrigeration, 1/3 Dvoryanskaya Str., Odessa 65082, Ukraine
E-mail: unive@icn.od.ua

Received December 5, 2012


We made an attempt to predict location of the melting line of polymeric nitrogen using two equations for Helmholtz free energy: proposed earlier for cubic gauche-structure and developed recently for liquid polymer-ized nitrogen. The P–T relation, orthobaric densities and latent heat of melting were determined using a standard double tangent construction. The estimated melting temperature decreases with increasing pressure, alike the temperature of molecular–nonmolecular transition in solid. We discuss the possibility of a triple point (solid–molecular fluid–polymeric fluid) at ~ 80 GPa and observed maximum of melting temperature of nitrogen.

PACS: 05.70.Ce Thermodynamic functions and equations of state;
PACS: 61.66.Bi Elemental solids;
PACS: 61.50.Ah Theory of crystal structure, crystal symmetry; calculations and modeling;
PACS: 64.70.dj Melting of specific substances.

Key words: solid nitrogen, polymerization, phase transition, equation of stare.