Crystal growth and some properties of REMn2Si2 (RE = Er, Tm, Yb, Lu) compounds

Single crystals of REMn2Si2 (RE = Er, Tm, Yb, Lu) were grown from a high-temperature lead metal flux in an Ar atmosphere. The REMn2Si2 crystals were plates enclosed by large {101} faces, and small {100} and {101} faces; maximum crystal size was 2.5 x 2.5 x 0.02 mm. Chemical analyses of the crystals show the chemical composition with atomic ratios RE (RE = Er, Tm, Yb, Lu):Mn:Si = 1:2:2. The values of the micro-Vickers hardness for the {001} faces of ErMn2Si2, TmMn2Si2, YbMn2Si2 and LuMn2Si2 are 5.0 + 0.4, 6.3 + 0.3, 7.9 + 0.3 and 6.1 + 0.4 GPa, respectively. According to thermogravimetric and differential thermal analyses, the oxidation of ErMn2Si2, TmMn2Si2, YbMn2Si2 and LuMn2Si2 crystals began to proceed at about 778, 978, 987, and 974 K, respectively. The results of magnetic susceptibility measurements down to low temperatures of the compounds are discussed. (C) 2002 Elsevier Science B.V. All rights reserved.