Neutron scattering studies of the spin ices Ho2Ti2O7 and Dy2Ti2O7 in applied magnetic field

TL;DR

This study uses neutron diffraction to explore how magnetic fields influence the complex spin arrangements and dynamics in Ho2Ti2O7 and Dy2Ti2O7 spin ice materials, revealing ordered states, chain formations, and slow dynamics.

Contribution

It provides new insights into the field-induced magnetic ordering and partial ordering phenomena in spin ice materials using neutron scattering.

Findings

Long-range order along [001] field direction.

Formation of quasi-one-dimensional chains along [1-10].

Observation of metastable states and slow dynamics.

Abstract

Neutron diffraction has been used to investigate the magnetic correlations in single crystals of the spin ice materials Ho2Ti2O7 and Dy2Ti2O7 in an external magnetic field applied along either the [001] or [1-10] crystallographic directions. With the field applied along [001] a long range ordered groundstate is selected from the spin ice manifold. With the field applied along [1-10] the experiments show that the spin system is separated into parallel (alpha) and perpendicular (beta) chains with respect to the field. This leads to partial ordering and the appearance of quasi-one-dimensional magnetic structures. In both field orientations this frustrated spin system is defined by the appearance of metastable states, magnetization plateaux and unusually slow, field regulated dynamics.