Boron-induced valence change of cerium in CePd₃

Abstract

It is found that boron can be added to CePd₃ to form compounds having the formula CePd₃B_x where x typically lies between 0 and 1. Addition of boron causes an expansion in cell volume without a change in the structure. The increase in cell volume as a function of boron concentration is much larger in CePd₃B_x compounds compared with that in LaPd₃B_x or GdPd₃B_x compounds. While CePd₃ is a well-known mixed-valent system, susceptibility and lattice-parameter measurements show that the addition of boron to CePd₃ causes a change in the valence state of cerium from a mixed-valent to an almost trivalent state. The change is striking in going from CePd₃ to CePd₃B_0.12.