ThearealdistributionofsomeelementsintherareearthbearingspheroidalphasesinpurealuminiumandAl-MnalloyswasstudiedbySIMS(secondaryionmassspectrometry).Theresultsshowthatcerium,iron.siliconandhydrogenaresignificantlysegregatedinthephases.Thustheexistenceofhydrogen-richrareearthbearingeompoundsisconfirmed.Itindicatesthattherareearthshaveahydrogenfixationeffectinaluminiumandaluminiumalloys.