title: Anomalous thermal expansion in the square-net compounds RE4TGe8 (RE = Yb, Gd; T = Cr-Ni, Ag).
abstract: The family of materials RE(4)TGe(8) (RE = Yb, Gd; T = transition metal) exhibits directional zero thermal expansion (ZTE) via a process that is associated with the linking of planar square nets in the third dimension. The Ge square nets in these compounds exhibit commensurate long-range modulations similar to those observed in charge-density-wave compounds. The ZTE is manifested in the plane of the square nets from 10 to 300 K with negligible volume expansion below ∼160 K. The specific atomic arrangement in RE(4)TGe(8) enables a Poisson-like mechanism that allows the structure to contract along one direction as it expands only slightly in the perpendicular direction.
authors.affiliation: Department of Chemistry, Northwestern University, Evanston, Illinois 60208, United States.
authors.forename: Sebastian C
authors.initials: SC
authors.lastname: Peter
authors.forename: Maria
authors.initials: M
authors.lastname: Chondroudi
authors.forename: Christos D
authors.initials: CD
authors.lastname: Malliakas
authors.forename: Mahalingam
authors.initials: M
authors.lastname: Balasubramanian
authors.forename: Mercouri G
authors.initials: MG
authors.lastname: Kanatzidis