CRYSTAL DYNAMICS OF PT3MN AT 80-K

The frequencies of the normal modes of vibration of ordered Pt 3Mn have been measured at 80K using neutron inelastic scattering techniques. Extensive measurements have been made of the modes propagating along the (100), (110) and (111) high symmetry directions. Born-von Karman force constant models have been fitted to the experimental results and show that the Pt-Mn forces are only approximately 20% of the Pt-Pt forces in pure Pt. A comparison has been made between the crystal dynamics of Pt3Mn and Pd3Fe.