Ferromagnetic Ising Spin Chains Emerging from the Spin Ice under Magnetic Field

TL;DR

This study investigates how applying a magnetic field to the spin-ice compound Dy2Ti2O7 induces ferromagnetic Ising spin chains, revealing new specific heat peaks and chain behaviors under field influence.

Contribution

It demonstrates the emergence of ferromagnetic Ising spin chains in spin ice under magnetic fields, providing insights into chain formation and magnetic behavior.

Findings

Sharp specific heat peak at 1.1 K appears above 0.4 T

Perpendicular chains behave as ferromagnetic Ising spin chains

Field-independent peak up to 1.5 T

Abstract

A spin-ice compound dysprosium titanate, Dy2Ti2O7, is studied by specific heat measurements in magnetic fields applied along the [110] direction of the cubic unit cell. Above a magnetic field of 0.4 T a relatively sharp peak at T = 1.1 K in the specific heat appears from a broad peak associated with spin-ice freezing at low fields. This new peak is almost independent of field up to 1.5 T, while another broad, field-dependent peak is detected at higher temperature. Under magnetic field along [110] Ising spins on the pyrochlore lattice can be considered to form two orthogonal sets of chains; parallel and perpendicular to the field direction. It is suggested that these perpendicular chains behave as unique ferromagnetic Ising spin chains without long-range order.