From Infinity to Zero and Back Again to Infinity (From Mixed Rare Earths to Ultrapure Metals to Pseudo-Lanthanides)

摘要

This paper concerns two topics with which the author is involved. The first is the continuing effort to purify the rare earth metals beyond four nines (99.99 at. %) purity. It appears that we are on the threshold of a major advance - five nines purity on an atomic basis with respect to all the elements in the periodic table. The second topic is the contamination (alloying) of the high purity rare earth metals (99.9 at. %) with each other to form pseudo-lanthanides. The main thrust for this act of madness after all the effort to purify them is to use these pseudo-lanthanides to (1) unravel the various contributions to the heat capacity so that we can better understand the electronic and magnetic nature of the lanthanide elements and their compounds; and (2) to prepare new superconducting compounds, which may have interesting and hopefully useful superconducting properties. (ERA citation 05:022641)