Neutron depolarization due to ferromagnetism and spin freezing in <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mrow><mml:msub><mml:mi>CePd</mml:mi><mml:mrow><mml:mn>1</mml:mn><mml:mo>−</mml:mo><mml:mi>x</mml:mi></mml:mrow></mml:msub><mml:msub><mml:mi>Rh</mml:mi><mml:mi>x</mml:mi></mml:msub></mml:mrow></mml:math>

Marc Seifert, Philipp Schmakat, Michael Schulz, Pau Jorba, Vladimir Hutanu, C. Geibel, M. Deppe, C. Pfleiderer

Abstract

We report neutron depolarization measurements of the suppression of long-range ferromagnetism and the concomitant emergence of magnetic irreversibilities and spin freezing in ${\mathrm{CePd}}_{1\ensuremath{-}x}{\mathrm{Rh}}_{x}$ around ${x}^{*}\ensuremath{\approx}0.6$. Tracking the temperature versus field history of the neutron depolarization, we find clear signatures of long-range Ising ferromagnetism below a Curie temperature ${T}_{\mathrm{C}}$ for $x=0.4$ and a spin freezing of ferromagnetic clusters below a freezing temperature ${T}_{\mathrm{F}1}$ for $x&gt;{x}^{*}$. Under zero-field-cooling/field-heating and for $x&gt;{x}^{*}$ a reentrant temperature dependence of the neutron depolarization between ${T}_{\mathrm{F}2}&lt;{T}_{\mathrm{F}1}$ and ${T}_{\mathrm{F}1}$ is microscopically consistent with a thermally activated growth of the cluster size. The evolution of the depolarization as well as the reentrant temperature dependence as a function of Rh content are consistent with the formation of a Kondo cluster glass below ${T}_{\mathrm{F}1}$ adjacent to a ferromagnetic quantum phase transition at ${x}^{*}$.

Locations

• Physical Review Research - View - PDF
• arXiv (Cornell University) - View - PDF