Dynamical behaviour of ultrathin [CoFeB (t)/Pd] films with perpendicular magnetic anisotropy.

CoFeB-based ultrathin films with perpendicular magnetic anisotropy are promising for different emerging technological applications such as nonvolatile memories with low power consumption and high-speed performance. In this work, the dynamical properties of [CoFeB (t)/Pd (10 Å)] multilayered ultrathin films (1 Å ≤ t ≤ 5 Å) are studied by using two complementary methods: time-resolved magneto-optical Kerr effect and broadband ferromagnetic resonance. The perpendicular magnetization is confirmed for multilayers with t ≤ 4 Å.