THERMODYNAMIC CALCULATION OF Ga–N MELTING DIAGRAM UNDER ATMOSPHERIC AND HIGH PRESSURES

V. Z. Turkevich; Yu. Yu. Rumiantseva; D. V. Turkevych; O. I.   Chernienko; O. V. Savitskyi; S. O. Hordieiev; O. V.  Kushch; Yu. I. Sadova

V. N. Bakul Institute for Superhard Materials of National Academy of Sciences of Ukraine
Yu. Yu. Rumiantseva V. N. Bakul Institute for Superhard Materials of National Academy of Sciences of Ukraine
D. V. Turkevych V. N. Bakul Institute for Superhard Materials of National Academy of Sciences of Ukraine
O. I. Chernienko V. N. Bakul Institute for Superhard Materials of National Academy of Sciences of Ukraine
O. V. Savitskyi V. N. Bakul Institute for Superhard Materials of National Academy of Sciences of Ukraine
S. O. Hordieiev V. N. Bakul Institute for Superhard Materials of National Academy of Sciences of Ukraine
O. V. Kushch V. N. Bakul Institute for Superhard Materials of National Academy of Sciences of Ukraine
Yu. I. Sadova V. N. Bakul Institute for Superhard Materials of National Academy of Sciences of Ukraine

Keywords: GaN, high pressures, thermodynamic calculations, ThermoCalc

Abstract

It was done melting diagram calculation of Ga–N system at atmospheric pressure (0,1 MPa) and at high pressures (1, 4, 6 GPa) within the phenomenological thermodynamics models. It is shown that increasing of pressure up to 6 GPa doesn't lead to the new phases formation, but allows to extend the temperature range of gallium nitride wurtzite modification stability up to 2615 K (the temperature above which the gas-peretechnic reaction (2GaN ⇆ 2Ga_L + N₂↑) occurs).