Nanostructure iron oxyfluoride compounds of tunable oxygen content were fabricated by a solution process utilizing iron metal and fluorosilicic acid solutions as precursors. Simple adjustment of the synthesis atmosphere, temperature, and time enabled the fabrication of iron oxyfluoride materials with compositions spanning over the entire range from pure FenormalF2 to FeOF. Nanocomposites were fabricated from iron oxyfluorides of various oxygen content and activated carbon in order, for the first time, to evaluate the impact of oxygen on the iron fluoride electrochemical performance. The introduction of oxygen proved beneficial to cycling stability but at the expense of reversible capacity. A combination of electrochemical and structural characterization analyses was performed to identify the iron oxyfluoride reaction mechanism.

HEATS OF ~~' O I~M A T I O NO F UNSTABLE G a s~~v s HYDRIDES 779 results into eq. 15 yields DiscussionIf the attractive forces vanish, 8 = 0 and eq. 16 reduces to Az" = 1, as required for hard spheres.Sumerical solution of eq. 16 for the Flory temperature, 8 , givm

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A bomb calorimeter for measuring the heat of detonation of 25 g charges of high explosive is described. A complete calorimetric measurement can be made in 1 h with a precision of 0.3%. Calorimetric measurements and analysis for PETN are described. The data are interpreted with the aid of thermodynamic and hydrodynamic computer calculations. For unconfined or lightly confined charges, the released energy is largely retained in the products which are shocked considerably off the Chapman-Jouguet isentrope by reflections from the bomb wall. For heavily confined charges, the energy is largely converted to kinetic and internal energy of the confining case, and the essentially unshocked products expand along the Chapman-Jouguet isentrope. The products of detonation are found to freeze out at 1500 to 1800°K. The heat of detonation of PETN at 298°K is 1490±6 cal/g, H2O(l).

an efficient proton scavenger.11 Our data indicate that a trace of NH3 (1.5 mole %) completely stops the disappearance of CD4. This effect is similar to that of Xe in the radiation-induced H2-D2 exchange.2 Preliminary experiments indicate that Xe is not effective as a proton scavenger in the CH4-D2 system. Findings to date indicate that proton-transfer efficiencies may be ranked in the order NH3 > CH4 > Xe > D2, and that this order may be the same as that for the proton affinities of these molecules. Judicious use of NH3 to block ionic reactions in the D2-TD-CH4 system may permit accurate evaluation of the temperature coefficient for the atomic exchange reaction. Work directed toward establishment of a more inclusive scale of relative protontransfer efficiencies and toward elucidation of the atomic and free-radical exchange mechanism for CH4 and D2 is in progress.12