Determination of the magnetization scaling exponent for single crystal La$_{0.8}$Sr$_{0.2}$MnO$_3$ by broadband microwave surface impedance measurements

Andrew Schwartz; Marc Scheffler; Steven M. Anlage

doi:10.1103/PhysRevB.61.R870

paper

Determination of the magnetization scaling exponent for single crystal La $_{0.8}$ Sr $_{0.2}$ MnO $_{3}$ by broadband microwave surface impedance measurements

arXiv:cond-mat/9910481 · doi:10.1103/PhysRevB.61.R870

Abstract

Employing a broadband microwave reflection configuration, we have measured the complex surface impedance, $Z_{S} (ω, T)$ , of single crystal La $_{0.8}$ Sr $_{0.2}$ MnO $_{3}$ , as a function of frequency (0.045-45 GHz) and temperature (250-325 K). Through the dependence of the microwave surface impedance on the magnetic permeability, $μ^(ω, T)$ , we have studied the local magnetic behavior of this material, and have extracted the spontaneous magnetization, $M_{0} (T)$ , in {\em zero applied field}. The broadband nature of these measurements and the fact that no external field is applied to the material provide a unique opportunity to analyze the critical behavior of the spontaneous magnetization at temperatures very close to the ferromagnetic phase transition. We find a Curie temperature $T_{C} = 305.5 \pm 0.5$ K and scaling exponent $β = 0.45 \pm 0.05$ , in agreement with the prediction of mean-field theory. We also discuss other recent determinations of the magnetization critical exponent in this and similar materials and show why our results are more definitive.

4 pages; 3 figures included with epsfig; to be published in Phys. Rev. B Rapid Communications

Determination of the magnetization scaling exponent for single crystal La0.8​Sr0.2​MnO3​ by broadband microwave surface impedance measurements

Abstract

Cited by in corpus (17)

Determination of the magnetization scaling exponent for single crystal La $_{0.8}$ Sr $_{0.2}$ MnO $_{3}$ by broadband microwave surface impedance measurements