Compression of Fe3C to 30 GPa at room temperature

Polycrystalline Fe3C (cementite) was compressed in a neon pressure medium to 30.5 GPa at 300 K using diamond-anvil cell techniques. Angular dispersive X-ray diffraction of Fe3C was measured using monochromatic synchrotron radiation and imaging plates. No phase transition was observed up to the highest pressure studied. The pressure-volume data were fitted to a third-order Birch-Murnaghan equation of state. With V-0 constrained to a measured value of 155.28 Angstrom(3), the best fit yielded a 300-K isothermal bulk modulus K-0 = 174 +/- 6 GPa, and its pressure derivative at constant temperature K-0' = (partial derivativeK(0)/partial derivativeP)(T) = 4.8 +/- 0.8.