Figure 6: Calculated temperature dependence of the penetration depth ( ) for LaFeAsO F (  K, red solid line), Ba K Fe As (  K, dash blue line), and for SmFeAsO F (  K, green dash-dot line). The insert shows the behaviour of obtained by solution of Eliashberg equations: red circles for LaFeAsO F , dark blue triangle for Ba K Fe As , green squares for SmFeAsO F . The lines are the third-order polynomial fits.