The microscopic model for the magnetic subsystem in HoNi2B2C

TL;DR

This paper presents a 4-positional clock model for the magnetic subsystem in HoNi2B2C, accurately reproducing experimental phase diagrams and magnetic modulations, including near the Curie temperature.

Contribution

It introduces a novel 4-positional clock model incorporating non-nearest neighbor couplings to describe magnetic phases in HoNi2B2C.

Findings

Model reproduces experimental phase diagram.

Accurately predicts magnetic modulation wave-vector.

Explains magnetic behavior near Curie temperature.

Abstract

We demonstrate that the system of localized magnetic moments in HoNi$_2$B$_2$C can be described by the 4-positional clock model. This model, at a proper choice of the coupling constants, yields several metamagnetic phases in magnetic field at zero temperature in full agreement with the experimental phase diagram. The model incorporates couplings between not nearest neighbors in the direction perpendicular to the ferromagnetic planes. The same model leads to a c-modulated magnetic phase near the Curie temperature. The theoretical value of the modulation wave-vector agrees surprisingly well with that observed by the neutron diffraction experiment without new adjustable parameters.