Data for Near-ideal molecule-based Haldane spin chain

The Haldane gap is closed by orientation-dependent critical fields μ0Hc∥ = 5.3 T and μ0Hc⊥ = 4.3 T, which are readily accessible experimentally and permit investigations across the entirety of the Haldane phase, with the fully polarized state occurring at μ0Hs∥ = 46.0 T and μ0Hs⊥ = 50.7 T. The results are explicable within the so-called fermion model, in contrast to other reported easy-axis Haldane systems. Zero-field magnetic order is absent down to 20 mK and emergent end-chain effects are observed in the gapped state, as evidenced by detailed low-temperature measurements.<br><br>Zip file containing data files in .dat format underpinning figures in related publication.

Data for fig. 2a shows temperature (X) against magnetic susceptibility (Y). Data for fig.s 2b, 2c and 2d show magnetisation (X) plotted against magnetic fields in tesla (Y). Data for fig.s 3a and 3b show single-crystal magnetisation (Y) as a function of applied magnetic field (X) with the field applied parallel (II) and perpendicular (perp) to the unique crystallographic c-axis (z) and the 2nd differential.

Full data for fig. 4a can be accessed at isis.stfc.ac.uk/Pages/Data-Policy.aspx with the DOI 10.5286/ISIS.E.RB1810129 Data for fig. 4b shows energy transfers (X), counts (Y) and error (Z) on the counts for inelastic neutron scattering data at 1.8, 4 and 7 kelvin temperatures at ISIS RAL, UK. Full data can be accessed as described in the above Fig4a text. Data for fig. 5 is spectral intensity plotted against field shift, with the plots normalised so that the maximum spectral intensity is 1.

Data for fig. 6 is column 7 (HWHM1) plotted against column 1 (applied field B). In the data files HWHM is specified rather than the FWHM so values differ by a factor of 1/2 from those included in the plot. Data above B=4.4T was fitted to a constant value.

Data below B=4.4 T was fitted to a straight line constrained to agree with the constant value fit at B=4.4 T. Data for fig.s 7a and 7b show frequency dependence of the ESR transmission spectrum (Y) measured against applied magnetic field (X). Data for fig. 7c contains 13 double columns of the ESR resonant frequencies (Y2) in Giga-Hertz against field (X1) making us the first double column and their respective fits (Y2) plotted against applied magnetic field (X1) making up the second.

Resonances are for simulations with the field parallel the the unique crystallographic c-axis (II z) and perpendicular to it (perp z) as well as the half-field transitions. End-chains resonances are also included. See manuscript for further details.

Data for fig. 8 contains energy level transitions in kelvin for the field parallel the the c-axis (E_z) and perpendicular (E_x) and how they develop with applied field dependant on magnetic quantum number mz = +1,0,-1. Data for fig.s 9a, 9b, 9c and 9d show the positions in millimetres (mm) and Total, subtracted and background raw SQUID responses in electromagnetic units (emu) for data in an applied magnetic field. Full data for fig.s 10a and 10b can be accessed at isis.stfc.ac.uk/Pages/Data-Policy.aspx with the DOI 10.5286/ISIS.E.RB1810129 Data for fig.s 11a, 11b and 11c are broken down into upper and lower panels.

Each shows energy transfer at a fixed meV rep-rate, counts (Y) and error (Z) for a given temperature. The data is a cut over all |Q|-space. All full data can be accessed as described in the above Fig4a text.

Data for fig. 12 contains the data and fits for the respective temperatures as shown in Figure 12. Data for fig. 13 contains the values of lambda seen in Figure 13.