High pressure neutron powder diffraction study of Fe_1−xCr_x with and without hydrogen exposure

The crystal structure of Fe_1−xCr_x(x = 0, 0.2 and 0.4) materials, with and without exposure to Hydrogen, is investigated using neutron powder diffraction under the applied external high-pressure. Above a certain applied pressure, P_C, a structural phase transition, from cubic to hexagonal symmetry, is observed, in agreement with previous x-ray diffraction results. The P_C values exhibit an increase with x increase. The possibility for an evolution of a magnetic structure with pressure, x and Hydrogen exposure, is examined. Finally, a broadening of the angular profile of the (200) reflection (cubic phase) is identified and reported