1202.0369 (T. Nakada et al.)

Neutron Scattering Study on Commensurate and Incommensurate
Antiferromagnetic Phases in UPd2Si2 under Uniaxial Stress    [PDF]

T. Nakada, M. Yokoyama, C. Tabata, H. Igarashi, H. Hidaka, H. Amitsuka, K. Tenya, T. J. Sato

The nature of competition between incommensurate (IC) and commensurate (C)
antiferromagnetic (AF) orders in UPd2Si2 was investigated by performing elastic
neutron scattering experiments under uniaxial stress sigma. It is found that
applying sigma along tetragonal [010] direction reduces the IC-AF order, and
then stabilizes the C-AF order. The transition temperature from IC- to C-AF
phases T_Nl is enhanced from 109 K (sigma=0) to 112.5 K (0.8 GPa), while the
onset of IC-AF transition T_Nh is unchanged from 132 K under sigma. In
addition, c-axis component q_z of the IC-AF modulation at 115 K also increases
from 0.736 (sigma=0) to 0.747 (0.8 GPa). The magnitude of C-AF moment at 5 K is
estimated to be 2.2 mu_B/U in the entire sigma range presently investigated
(sigma <= 0.8 GPa). These features are similar to those obtained from the
investigations using hydrostatic pressure p, indicating that applications of p
and sigma||[010] commonly induce the crystal strains which inherently affect a
delicate balance of frustrated magnetic interactions between uranium 5f
moments.

View original: http://arxiv.org/abs/1202.0369