Temperature dependence of magnetization-induced second harmonic generation at buried exchange-biased interfaces

Abstract

We have investigated the temperature dependence of magnetization-induced optical second harmonic generation (MSHG) in the exchange-biased $\mathrm{Co}\mathrm{O}∕\mathrm{Cu}∕\mathrm{Fe}$ multilayer. Below the blocking temperature, there is a strong MSHG response from the $\mathrm{Co}\mathrm{O}∕\mathrm{Cu}$ interface which, for large exchange bias values, equals and even dominates the contribution of the ferromagnetic Fe interfaces. In a previous publication we showed that there is a correlation between exchange bias and the MSHG asymmetry. Here we demonstrate the relationship between the second harmonic Kerr rotation and exchange bias and, based on that, we offer additional evidence that pinned uncompensated spins are present beyond the range of Cu spacer thickness where a hysteresis loop shift is observed.