Figure 2
Anisotropy field and anisotropy constants of CFB free layers with different non-magnetic impurities. (a) Solid symbols show Hk measured by FMR between 300 to 400 K for five different film stacks. Solid lines show linear fits to the data. (b) Symbols show Ki calculated from experimentally measured values of Ms and Hk, and fitted using a power law dependence on Ms(T)γ (solid lines). The inset shows the exponent γ as a function of M0 for free layers with different impurity amounts. (c) Hk data shown in (a) are compared with the values calculated from the temperature variations of Ms and Ki over an extended function of temperature. The inset shows the discrepancy in temperatures at which Hk vanishes between a linear approximation and the calculation. (d) Comparison of Hk models for devices (solid lines) and full films (dashed lines) of select stacks. The device model assumed a circular 70 nm diameter device. (e) Comparison of KefftFL (open) and Ki (solid) as a function of temperature.
