Fig. 2: Structural order parameter of Ta2Ni(Se,S)5.
From: Anomalous excitonic phase diagram in band-gap-tuned Ta2Ni(Se,S)5
a Change of the inter- and intra-chain Ta-Ta bond angle β − 90∘ as a function of temperature and S-doping. Error bars are determined based on the fitting error of the Bragg peak positions. b Top: experimental and DFT calculated β − 90∘ at zero temperature. Bottom: structural transition temperature Ts as a function of S-doping level, determined from XRD and resistivity measurement.
