Boron-induced valence change of cerium in CePd<SUB>3</SUB>

It is found that boron can be added to CePd3 to form compounds having the formula CePd3Bx 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 CePd3Bx compounds compared with that in LaPd3Bx or GdPd3Bx 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 CePd3B0.12