836.    EMMETT, P. H., HENDRICKS, S. B., AND BRUNAUER, S.  Dissociation Pressure of Fe4N.  Jour. Am. Chem. Soc., vol. 52, 1930, pp. 1456-1464; Chem. Abs., vol. 24, 1930, p. 2940.

     By a flow method it was determined that at 1 atm. pressure the % NH3 in a gaseous H2-NH3 mixture in equilibrium with an Fe-Fe4N mixture is 36 at 420, 30 at 444, 28.5 at 460, and 17 at 525.  The dissociation pressures of Fe4N at these respective temperatures are calculated to be 4,250, 4,300, 5,400, and 5,600 atm.