Interlayer correlation of Fe spins and charges in the 2-D triangular ferrimagnet ErFe 2O 4

Abstract

Neutron polarization analysis was applied to Bragg lines at (⅓, ⅓, l) and (⅔, ⅔, l) of an ErFe 2O 4 single crystal at 15 K. The magnetic scattering intensity is composed of three sinusoidal curves, corresponding to the spin correlations between next-nearest-neighbor Fe Fe or Fe Er layers. The correlation length along the c-axis is only about 8 Å, in contrast to 50 Å in the c-plane. The nuclear part of the scattering indicates correlation of atomic displacements up to about 50 Å along the c-axis, independent of the spin ordering.