. ▁Due ▁to ▁the ▁is ost ruct ural ▁nature ▁of ▁the ▁rare - ear th ▁hex abor ides ▁and ▁the ▁strong ▁interaction ▁of ▁bor on ▁oct ah ed ra ▁within ▁the ▁cry stal , ▁these ▁comp ounds ▁show ▁a ▁high ▁degree ▁of ▁lattice ▁matching ▁which ▁suggests ▁the ▁possibility ▁of ▁do ping ▁by ▁subst itut ing ▁one ▁rare ▁earth ▁metal ▁within ▁the ▁cry stal ▁with ▁another . ▁ ▁Until ▁recently , ▁it ▁had ▁been ▁hypoth es ized ▁that ▁er b ium ▁hex abor ide ▁was ▁un stable ▁due ▁to ▁the ▁small ▁size ▁of ▁the ▁Er 3 + ▁c ation ▁within ▁the ▁cry stal ▁structure ▁when ▁compared ▁to ▁the ▁ion ic ▁rad ii ▁of ▁other ▁rare - ear th ▁elements ▁that ▁form ▁known ▁rare - ear th ▁hex abor ide ▁comp ounds . ▁ ▁It ▁has ▁now ▁been ▁demonstrated , ▁however , ▁that ▁new ▁nan osc ale ▁synth etic ▁methods ▁are ▁capable ▁of ▁producing ▁high - p urity , ▁stable ▁er b ium ▁hex abor ide ▁nan ow ires . ▁These ▁w ires , ▁produced ▁using ▁chemical ▁v apor ▁de position ▁( C VD ), ▁have ▁a ▁reported ▁lattice ▁constant ▁of ▁ 4 . 1 ▁Å . ▁ ▁References ▁▁ ▁Category : Er b ium ▁comp ounds <0x0A> </s> ▁Robert ▁E . ▁F ass n acht ▁ ▁( J anu ary ▁ 1 4 , ▁ 1 9 3 7 ▁– ▁August ▁ 2 4 , ▁ 1 9 7 0 ) ▁was ▁an ▁American ▁physics ▁post - do ctor al ▁research er ▁who ▁was