First Step In Exploration Of Fe-Ga-N System For Efficient Crystallization Of Gan At High N-2 Pressure

According to the existing data, iron is a very efficient solvent for nitrogen. In this work, the results of first steps toward crystallization of GaN from Fe-based solutions at 1 GPa N-2 pressure are reported. Melting of Fe at 0.88 GPa N-2 pressure is studied by differential thermal analysis (DTA) which shows a strong (approximate to 200 degrees C) decrease of melting temperature as compared to the well-established value of 1570 degrees C for pure Fe at 0.88 GPa at inert atmosphere. The N content of about 11.9 at.% is found by ON836 LECO analyzer in the Fe samples after DTA. It means that the observed drop of T-m (Fe) is related to the high solubility of nitrogen in Fe metal. Also the dissolution of GaN in Fe in 1370-1480 degrees C temperature range is studied. Encouragingly high (22-30 at.%) solubilities of Ga (direct measurement) and most probably, as high for N (evaluated from mass balance) are found.