Short Range Magnetic Order in a Chiral Helimagnet Yb(Ni 1− x Cu x ) 3 Al 9

Abstract Yb(Ni 1− x Cu x ) 3 Al 9 ( x = 0 and 0.06) are chiral magnets containing 4 f -electrons. The chiral helimagnetism arises from Dzyaloshinskii-Moriya (DM) interactions within the chiral crystal structure. Neutron scattering experiments on the samples with x = 0 and 0.06 reveal chiral helimagnetic (CHM) ordering below 2.8 and 6.5 K, respectively. The helical propagation vectors for x = 0 and 0.06 are approximately q = (0,0,0.83) and (0,0,0.43). Both samples exhibit a diffusive magnetic peak only along the c axis below T N . The application of a magnetic field perpendicular to the c -axis suppresses the CHM and diffuse scattering. Polarized neutron scattering experiments successfully determined the ratio of the left- and right-handed helical domains of the YbNi 3 Al 9 crystal.