Combined Transport, Magnetization and Neutron Studies of Structural and Magnetic Behavior in Ca3Ir4Sn13

Ca3Ir4Sn13, synthesized by Espinosa and his coworkers almost 30 years ago, was recently suggested to possess an unconventional superconducting ground state in the presence of a background of strong spin fluctuations. This signature for this claim stemmed from charge transport and magnetization anomalies near 45K, yet, later a detailed single crystal XRD investigation revealed that the anomaly is produced by a second order superlattice transition and that this transition can be tuned to zero temperature---suggesting a structural quantum critical point. Here in an attempt to characterize this phase further, we present a picture of the evolution of the structural and magnetic behavior in Ca3Ir4(Sn1-xSbx)13 via a combined transport, magnetization and neutron scattering study.