Quasi-two-dimensional ferromagnetism in the triangular magnet EuAl$_{12}$O$_{19}$

TL;DR

This study discovers quasi-two-dimensional ferromagnetism in EuAl$_{12}$O$_{19}$ with a Curie temperature of 1.3 K, highlighting strong anisotropy and field-tunable magnetic properties through experimental and simulation methods.

Contribution

The paper reports the first observation of ferromagnetic order in EuAl$_{12}$O$_{19}$ and analyzes its anisotropic magnetic behavior using experiments and Monte Carlo simulations.

Findings

Ferromagnetic order at 1.3 K in EuAl$_{12}$O$_{19}$

Strong uniaxial anisotropy along the c axis

Magnetic field suppresses Curie temperature to zero at 0.5 T

Abstract

We report ferromagnetic ordering at $T_\mathrm {C}=1.3\,$K in the quasi-two dimensional magnet EuAl$_{12}$O$_{19}$ with large spins $S=7/2$. This ferromagnetic state was characterized by magnetization and specific heat measurements and the experimental results were compared with classical Monte Carlo simulations. They reveal a strong single ion anisotropy leading to an uniaxial spontaneous magnetization along the $c$ axis. Furthermore the application of a magnetic field in the hard magnetization plane $ab$ reduces the Curie temperature and it reaches zero temperature at a magnetic field of $\mu_\mathrm{0} H_c \approx 0.5\,$T.