Impurity-Pinned Solitons in the Two-Dimensional Antiferromagnet Detected by Electron Paramagnetic Resonance

Abstract

It is shown that the introduction of a very small amount of nonmagnetic impurities into the magnetic sites of a classical two-dimensional antiferromagnet creates a new type of static (impurity-pinned) soliton that affects the Arrhenius, $\mathrm{exp}(\ensuremath{-}E/T)$, temperature-dependent electron paramagnetic resonance linewidth by drastically changing the parameter $E$. Data just above the transition temperature for $({\mathrm{C}}_{3}{\mathrm{H}}_{7}{\mathrm{NH}}_{3}{)}_{2}{M}_{x}{\mathrm{Mn}}_{1\ensuremath{-}x}{\mathrm{Cl}}_{4}$ confirm the existence of these impurity-pinned solitons.