A relationship for crystal field strength along the lanthanide series;: application to the prediction of the (2F7/2)Yb3+ maximum splitting

Using the scalar field parameter N-v, calculated from the respective B-q(k) 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 F-2(7/2) ground state of Yb3+ assuming a knowledge of the maximum splitting of the Nd3+4I9/2 ground state. Because Nd3+ is less prone than Yb3+ to mix with vibronics, this approach helps to distinguish the highest Stark level of F-2(7/2) from vibronics, using the following prediction: The maximum splitting of the (F7/2Yb3+)-F-2 ground state in a given host site cannot be less than the one of Nd3+4I9/2 in the same crystal host site. (C) 2002 Elsevier Science B.V. All rights reserved.