Neutron Diffraction Studies On Valence Ordering Compound Ybpd

The magnetic structure of YbPd was determined for a newly synthesized strain-free sample by neutron diffraction techniques. The sinusoidal magnetic structure characterized by an incommensurate wave vector k = (0.080 0 0.32) is observed in the magnetic-ordered phase between T-3 = 1.9K and T-4 = 0.5 K, which is composed of the magnetic-moment amplitude of 0.3 mu(B) parallel to the alpha-axis in the tetragonal crystal-structure phase. The modulated magnetic structure is consistent with the previously proposed Yb-ion valence ordered structure appearing below T-2 = 105 K, which consists of the periodic arrangement of magnetic and nonmagnetic Yb ions.