Observation of 3D Heisenberg-like ferromagnetism in single crystal La_{0.875}Sr_{0.125}MnO_3

Abstract

We report measurements and analysis of the magnetic critical phenomena in a single crystal of La${_{0.875}}$Sr${_{0.125}}$MnO${_3}$. The critical exponents associated with the ferromagnetic transition have been determined from ac susceptibility and dc magnetisation data. Techniques like the Kouvel$-$Fischer plots, modified Arrots Plots and the critical isotherm analysis were used for this purpose. The values of the the exponents $γ$, $β$ and $δ$ obtained are found to match very well with those predicted for the 3D Heisenberg model. Our results are consistent with recent numerical calculations and suggest that though the double exchange interaction is driven by the motion of conduction electrons, the effective magnetic interaction near the transition is renormalized to a short range one.