Stability of the Helical Spin Structure in MnP

抄録

Seven different exchange constants have been chosen in order to explain the helical spin order in MnP which propagates along the orthorhombic a-axis, as observed by Felcher et al. by neutron diffraction experiment. Only isotropic exchange interactions are assumed. Using experimental data for the period of propagation, i.e., 9a (a is the largest side-length of the orthorhombic unit cell), and the phase difference of the two helices, i.e., 16°, the signs and relative magnitudes of the chosen exchange constants are discussed, and the region in the parameter space, where the observed helical spin order is stabilized, is determined.