Yttrium is a Block D, Group 3, Period 5 element. The electronic configuration is [Kr] 4d¹ 5s². In its elemental form yttrium's CAS number is 7440-65-5. The yttrium atom has a radius of 177.6.pm and it's Van der Waals radius is 200.pm. Yttrium has the highest thermo-dynamic affinity for oxygen of any element. This characteristic is the basis for many of its applications. While not part of the rare earth series, it resembles the heavy rare earths which are sometimes referred to as the “yttrics” for this reason. Another unique characteristic derives from its ability to form crystals with useful properties. Yttrium is available as metal and compounds with purities from 99% to 99.999% (ACS grade to ultra high purity); metals in the form of foil, sputtering target, and rod, and compounds as submicron and nanopowder.

Zirconium is a Block D, Group 4, Period 5 element. The electronic configuration is [Kr] 4d² 5s². In its elemental form zirconium's CAS number is 7440-67-7. The zirconium atom has a radius of 159.pm and it's Van der Waals radius is 200.pm. Zirconium is primarily used in it's oxide or zirconia form. Zirconium dioxide has a high melting point (2,700° C) and a low thermal conductivity. Its polymorphism, however, restricts its widespread use in ceramic industry. During a heating process, zirconia will undergo a phase transformation process. The change in volume associated with this transformation makes the usage of pure zirconia in many applications impossible.