title: Ternary rare-earth aluminium intermetallics RE10TAl3(RE = Y, Ho, Tm, Lu; T = Fe, Co, Ni, Ru, Rh, Pd, Os, Ir, Pt) with an ordered anti-Co2Al5structure.
abstract: Twenty new rare-earth metal rich intermetallic aluminium compounds, RE10TAl3(RE = Y, Ho, Tm, Lu; T = Fe, Co, Ni, Ru, Rh, Pd, Os, Ir, Pt), were synthesized by arc melting the elements. The compounds crystallize, in analogy to e.g. the respective Cd representatives, with a ternary ordered structure as anti-type to the hexagonal Co2Al5type, with the space group P63/mmc. The three crystallographically independent rare-earth metal sites occupy the aluminium positions of the aristotype, while the transition metal and aluminium atoms are ordered on the two cobalt sites. Like other rare-earth rich compounds the RE10TX3members also exhibit transition-metal-centred T@RE6trigonal prisms as striking structural building units. The prepared compounds have been investigated by susceptibility measurements and27Al solid-state MAS-NMR measurements conducted on the Pauli-paramagnetic Y and Lu compounds. Some compounds show a certain amount of disorder as seen from the single crystal structure analysis and from signal broadening in the NMR investigations. By separating Knight shifts from second-order quadrupolar shifts via field dependent measurements, monotonic trends can be discerned regarding the effect of the T atom valence electron concentration and period number, as well as the effect of the closed 4f shell contributed in the Lu compounds. The results confirm that a comparison of Knight shifts within a series of isotypic compounds can reveal important electronic structure information in intermetallic systems.
authors.affiliation: Institut für Anorganische und Analytische Chemie, Universität Münster, Corrensstrasse 28/30, 48149 Münster, Germany. ocjanka@uni-muenster.de and Institut für Physikalische Chemie, Universität Münster, Corrensstrasse 28/30, 48149 Münster, Germany.
authors.forename: Christopher
authors.initials: C
authors.lastname: Benndorf
authors.affiliation: Institut für Physikalische Chemie, Universität Münster, Corrensstrasse 28/30, 48149 Münster, Germany and Instituto de Física de São Carlos, Universidade de São Paulo, São Carlos, SP 13566-590, Brazil.
authors.forename: Hellmut
authors.initials: H
authors.lastname: Eckert
authors.affiliation: Institut für Anorganische und Analytische Chemie, Universität Münster, Corrensstrasse 28/30, 48149 Münster, Germany. ocjanka@uni-muenster.de and Institut für Chemie, Carl von Ossietzky Universität Oldenburg, Carl-von-Ossietzky-Strasse 9-11, 26129 Oldenburg, Germany.
authors.forename: Oliver
authors.initials: O
authors.lastname: Janka