Abstract:
In this letter we report our measurements of Er and PrL(3) edges in Er(1-x)Pr(x)Ba(2)Cu(4)O(8), 0 less than or equal to x less than or equal to 0.6. The normalized L(3)-edge intensity is seen to closely follow the behaviour of T(c) with the Pr concentration in these compounds. This can be related to the fact that there is a reduction in the number of mobile carriers with increasing Pr-doping level. This picture lends support to a recent model proposed by Liechtenstein and Mazin (Liechtenstein A I and Mazin II 1995 Phys. Rev. Lett. 70 1000) according to which the holes are localized in a band which crosses the Fermi level along with a hybridized state of 4f sup(2)L and 4f sup(1) at the Pr site, where L is a ligand hole.
