Chiu C. Tang | Searcharxiv

arXiv2015

Compositional dependence of anomalous thermal expansion in perovskite-like ABX3 formates

The compositional dependence of thermal expansion behaviour in 19 different perovskite-like metal-organic frameworks (MOFs) of composition [AI][MII(HCOO)3] (A = alkylammonium cation; M = octahedrally-coordinated divalent metal) is studied using variable-temperature X-ray powder diffraction measurements. While all systems show essentially the same type of thermomechanical response-irrespective of their particular structural details-the magnitude of this response is shown to be a function of AI and MII cation radii, as well as the molecular anisotropy of AI. Flexibility is maximised for large MII and small AI, while the shape of AI has implications for the direction of framework hingeing.

cond-mat.mtrl-sci↗

arXiv2013

Re-entrant Structural Phase Transition in a Frustrated Kagome Magnet, Rb2SnCu3F12

Rb2SnCu3F12 has been studied using synchrotron powder X-ray diffraction, powder neutron diffraction and single crystal X-ray diffraction at a range of temperatures (100 to 500 K). A broad but clear phase transition, possibly of re-entrant character, is found to occur in the powder form, whereas the corresponding transition is not seen in the single crystal.

cond-mat.str-el↗