title: Intermetallic compounds with near Zintl phase behavior: RE2Zn3Ge6 (RE = La, Ce, Pr, Nd) grown from liquid indium.
abstract: A series of compounds has been discovered while investigating reactions of rare earth, transition metals, and Ge in excess indium. These compounds, RE2Zn3Ge6 (RE = La, Ce, Pr, Nd), are isostructural, crystallizing in the orthorhombic space group Cmcm with lattice parameters a = 5.9691(9) angstroms, b = 24.987(4) angstroms, and c = 5.9575(9) angstroms for La2Zn3Ge6, a = 5.9503(5) angstroms, b = 24.761(2) angstroms, and c = 5.9477(5) angstroms for the Ce analogue, a =5.938(2) angstroms, b = 24.708(8) angstroms, and c = 5.936(2) angstroms for Pr2Zn3Ge6, and a = 5.9094(7) angstroms, b = 24.619(3) angstroms, and c = 5.9063(5) angstroms for the Nd analogue. The structure is composed of PbO-like ZnGe layers and ZnGe4 cage layers and is related to the Ce4Zn8Ge(11-x) structure type. The bonding in the system can be rationalized using the Zintl concept resulting in a material that is expected to be a valence precise semiconductor, although its behavior is more consistent with it being a semimetal, making it an intermediate case. The results of band structure calculations and magnetic measurements of these compounds are discussed.
authors.affiliation: Department of Chemistry, Michigan State University, East Lansing, Michigan 48842, USA.
authors.forename: James R
authors.initials: JR
authors.lastname: Salvador
authors.forename: Daniel
authors.initials: D
authors.lastname: Bilc
authors.forename: Jeffrey R
authors.initials: JR
authors.lastname: Gour
authors.forename: Subhendra D
authors.initials: SD
authors.lastname: Mahanti
authors.forename: Mercouri G
authors.initials: MG
authors.lastname: Kanatzidis