Rare Earth impurities in yb(6) and zrb(12).

We present data on the depression of the superconducting transition temperatures of YB(6) and ZrB(12) by rare earth impurities. These data show unusual features. Ce in YB(6) is in some ways analogous to Yb in ZrB(12), and this analogy also appears to hold between Ce in CeB(6) and YB in YbB(12).

Rare-earth elements and high pressures

Praseodymium, under very high pressures, shows a magnetic behavior similar to that of cerium at normal pressure.