Study of Gd/Co Multilayers with Different Cobalt Layer Thickness Values

The present work reports the magnetic and structural behavior of [Gd/Co]₁₀ multilayers with different Co thickness values, prepared by magnetron sputtering, as a function of thermal annealing. Intermixing is observed with thermal annealing for all the samples; however, complete intermixing is not observed even after annealing at 773 K. Antiparallel alignment of Gd and Co layer magnetization is observed for pristine samples from room temperature X-ray magnetic circular dichroism measurements. Magnetic compensation temperature is found to vary depending on the thickness of Co layers. Temperature-dependent magneto-optical Kerr effect (MOKE) measurements depict the inversion of loops across magnetic compensation temperature for all the pristine samples. However, no signatures of magnetic compensation are observed in the low-temperature MOKE loops for the annealed samples. MOKE loops of the annealed samples exhibit double hysteresis loops. The results are explained in terms of intermixing with annealing.