title: High-resolution neutron diffraction study of CuNCN: new evidence of structure anomalies at low temperature.
abstract: Copper carbodiimide (CuNCN) is the nitrogen-containing analogue of cupric oxide. Based on high-resolution neutron-diffraction data, CuNCN's lattice parameters are derived as a function of the temperature. In accordance with a recent synchrotron study, a clear trend in the cell parameter a is observed accompanying the changing magnetic behavior. With decreasing temperature, a slowly decreases to a minimum at ~100 K after which it rises again. The same trend-albeit more pronounced-is observed for the c lattice parameter at ~35 K. The herein presented neutron powder-diffraction data also support the conjectured sequence of transitions from the high-temperature one-dimensional resonating valence-bond (RVB) state to a transient two-dimensional RVB state and eventually, at lowest temperatures, into another two-dimensional RVB state, presumably the ground state.
authors: Institute of Inorganic Chemistry, RWTH Aachen University, D-52056 Aachen, Germany.
authors: Philipp
authors: P
authors: Jacobs
authors: Institute of Inorganic Chemistry, RWTH Aachen University, D-52056 Aachen, Germany.
authors: Andreas
authors: A
authors: Houben
authors: Institute of Inorganic Chemistry, RWTH Aachen University, D-52056 Aachen, Germany.
authors: Andrei L
authors: AL
authors: Tchougréeff
authors: Institute of Inorganic Chemistry, RWTH Aachen University, D-52056 Aachen, Germany.
authors: Richard
authors: R
authors: Dronskowski