A relationship for crystal field strength along the lanthanide series; application to the prediction of the maximum splitting

Abstract Using the scalar field parameter Nv, calculated from the respective Bkq parameters given in the literature for 115 different crystals, we show that a simple linear relationship between the number of f electrons and the crystal field strength can be found. From this result we derive the maximum splitting of 2 F 7/2 ground state of Yb3+ assuming a knowledge of the maximum splitting of the Nd 3+ 4 I 9/2 ground state. Because Nd3+ is less prone than Yb3+ to mix with vibronics, this approach helps to distinguish the highest Stark level of 2 F 7/2 from vibronics, using the following prediction: The maximum splitting of the 2 F 7/2 Yb 3+ ground state in a given host site cannot be less than the one of Nd 3+ 4 I 9/2 in the same crystal host site.