title: A25Mg,89Y and115In solid state MAS NMR study of YT2X and Y(T0.5T'0.5)2X (T/T' = Pd, Ag, Au; X = Mg, In) Heusler phases.
abstract: Yttrium-transition metal-magnesium (indium) Heusler phases YPd2Mg, YPd2In, YAg2Mg, YAg2In, YAu2Mg, and YAu2In and their quaternary compounds (solid solutions) Y(Pd0.5Ag0.5)2Mg, Y(Pd0.5Ag0.5)2In, Y(Pd0.5Au0.5)2Mg, Y(Pd0.5Au0.5)2In, Y(Ag0.5Au0.5)2Mg and Y(Ag0.5Au0.5)2In were synthesized from the elements in sealed niobium ampoules in a high-frequency furnace or by arc-melting, respectively. All compounds crystallize with the cubic MnCu2Al type structure (Heusler phase), space group Fm3[combining macron]m. The structure of Y(Ag0.39Au0.61)2Mg was refined from single crystal X-ray diffractometer data: a = 689.97(5) pm, wR2= 0.0619, 52 F2values, 6 parameters. Magnetic susceptibility measurements show Pauli paramagnetic behavior for all samples. The compounds were investigated by25Mg,89Y and115In solid state MAS NMR spectroscopy. Large positive resonance shifts are observed for all nuclei. A review of the present data in the context of literature data on isotypic Heusler phases with Cd and Sn indicates that the89Y shifts show a correlation with the electronegativity of the main group atoms (Mg, Cd, In, Sn). The solid solutions Y(Ag1-xTx)2Mg (x = 0.1, 0.25, 0.33, 0.5; T = Pd, Au) clearly show Vegard-like behavior concerning their lattice parameters, and their main group element resonance shifts arising from spin and orbital contributions are close to the interpolated values of the corresponding end-member compounds.
authors.affiliation: Institut für Anorganische und Analytische Chemie, Universität Münster, Corrensstrasse 30, D-48149 Münster, Germany. pottgen@uni-muenster.de and Institut für Physikalische Chemie, Universität Münster, Corrensstrasse 30, D-48149 Münster, Germany.
authors.forename: Christopher
authors.initials: C
authors.lastname: Benndorf
authors.affiliation: Institut für Anorganische und Analytische Chemie, Universität Münster, Corrensstrasse 30, D-48149 Münster, Germany. pottgen@uni-muenster.de.
authors.forename: Sebastian
authors.initials: S
authors.lastname: Stein
authors.affiliation: Institut für Anorganische und Analytische Chemie, Universität Münster, Corrensstrasse 30, D-48149 Münster, Germany. pottgen@uni-muenster.de.
authors.forename: Lukas
authors.initials: L
authors.lastname: Heletta
authors.affiliation: Institut für Anorganische und Analytische Chemie, Universität Münster, Corrensstrasse 30, D-48149 Münster, Germany. pottgen@uni-muenster.de.
authors.forename: Marcel
authors.initials: M
authors.lastname: Kersting
authors.affiliation: Institut für Physikalische Chemie, Universität Münster, Corrensstrasse 30, D-48149 Münster, Germany and Institute of Physics in Sao Carlos, University of Sao Paulo, CP 369, Sao Carlos, SP 13566-590, Brazil. eckerth@uni-muenster.de.
authors.forename: Hellmut
authors.initials: H
authors.lastname: Eckert
authors.affiliation: Institut für Anorganische und Analytische Chemie, Universität Münster, Corrensstrasse 30, D-48149 Münster, Germany. pottgen@uni-muenster.de.
authors.forename: Rainer
authors.initials: R
authors.lastname: Pöttgen