Yttric rare-earths

Y-section rayon, 11 262, 263 Ytterbium (Yb), 14 631t, 635t electronic configuration, l 474t Yttria, 5 583, 14 630 Yttria-stabilized zirconia (YSZ), 26 637 Yttric rare earths (RE), 14 631 Yttrium(III)... 

Under the classification of rare-earths, there are 15 lanthanide elements and the 2 elements appearing above lanthanum in the periodic table, scandium and yttrium [1]. The lanthanides are divided into two groups the first four elements are referred to as the ceric or light rare-earths, while the remaining are called the yttric or heavy rare-earths [2]. 

Compounds of equiatomic composition with rare-earth metals of the yttric and cerium subgroups crystallize with the ZrNiAl type whereas scandium germanide of equiatomic composition forms the MgAgAs type. 

An early classification of the rare earths (the oxides of lanthanides) in relation to their separation from ores, was in the ceritic earths (the oxides from lanthanum to samarium) and yttric earths (from europium to lutetium, but also scandium and yttrium). A further refinement of analytical methods made it possible to split the yttric earths into terbic (europium, gadolinium, terbium), erbic (dysprosium, holmium, erbium, thulium), and ytterbic (ytterbium and lutetium) earths, along with yttrium oxide and scandium oxide. 

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