Determination of the spin-flip time in ferromagnetic SrRuO3 from time-resolved Kerr measurements

TL;DR

This study measures the magnetization dynamics in SrRuO3 using time-resolved Kerr effect, revealing how demagnetization time varies near the Curie temperature and linking it to spin flip processes and damping.

Contribution

It provides the first direct estimation of spin-flip time in SrRuO3 from Kerr measurements and connects it to damping and temperature dependence.

Findings

Demagnetization time increases near T_c

Spin flip rate correlates with Gilbert damping

Demagnetization time inversely proportional to T - T_c

Abstract

We report time-resolved Kerr effect measurements of magnetization dynamics in ferromagnetic SrRuO3. We observe that the demagnetization time slows substantially at temperatures within 15K of the Curie temperature, which is ~ 150K. We analyze the data with a phenomenological model that relates the demagnetization time to the spin flip time. In agreement with our observations the model yields a demagnetization time that is inversely proportional to T-Tc. We also make a direct comparison of the spin flip rate and the Gilbert damping coefficient showing that their ratio very close to kBTc, indicating a common origin for these phenomena.