Compressibility of Nb2AsC to 41 GPa -: art. no. 111904

Room temperature synchrotron x-ray diffraction experiments were performed on the layered hexagonal ternary carbide Nb2AsC in a diamond anvil cell to a pressure of 41 GPa. The structure is stable with no phase transitions observed in this pressure range. The bulk modulus is 224 +/- 2 GPa, with a pressure derivative of 4; the former is the highest bulk modulus for a M(n+1)AX(n) (MAX) phase, including Ti3SiC2, measured to date. Nb2AsC is also the first MAX phase for which the compressibility along the a direction is higher than along the c direction; in other words, the c/a ratio increases strongly with applied pressure. (C) 2005 American Institute of Physics.