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Data for Asymmetric phase diagram and dimensional crossover in a system of spin-1/2 dimers under applied hydrostatic pressure M. J. Coak (24609780) S. P. M. Curley (25009771) Z. Hawkhead (24945631) J. P. Tidey (24966634) D. Graf (2733022) S. J. Clark (24883900) P. Sengupta (23477110) Z. E. Manson (24877225) T. Lancaster (2511082) P. Goddard (17181079) J. L. Manson (2472649) Hydrostatic pressure Pyrazines Glycine Magnetic fields Migrated from ePrints We present the magnetic and structural properties of [Cu(pyrazine)0.5 (glycine)]ClO4 under applied pressure. As previously reported, at ambient pressure this material consists of quasi-two-dimensional layers of weakly coupled antiferromagnetic dimers which undergo Bose-Einstein condensation of triplet excitations between two magnetic field-induced quantum critical points (QCPs). The molecular building blocks from which the compound is constructed give rise to exchange strengths that are considerably lower than those found in other S=1/2 dimer materials, which allows us to determine the pressure evolution of the entire field-temperature magnetic phase diagram using radio-frequency magnetometry. We find that a distinct phase emerges above the upper field-induced transition at elevated pressures and also show that an additional QCP is induced at zero-field at a critical pressure of pc=15.7(5),kbar. Pressure-dependent single-crystal X-ray diffraction and density functional theory calculations indicate that this QCP arises primarily from a dimensional crossover driven by an increase in the interdimer interactions between the planes. While the effect of quantum fluctuations on the lower field-induced transition is enhanced with applied pressure, quantum Monte Carlo calculations suggest that this alone cannot explain an unconventional asymmetry that develops in the phase diagram.<br><br>Data accompanying "Asymmetric phase diagram and dimensional crossover in a system of spin-1/2 dimers under applied hydrostatic pressure" by MJ Coak et al, 2023 This collection of the data presented in the above named manuscript is provided in the University of Warwick WRAP resarch data archive in order to allow open access to the data. Any questions should be directed to Paul Goddard at p.goddard@warwick.ac.uk. The data are split into two directories: - Crystal Information Files This contains the refined structural information discussed and plotted in the paper. The .cif files (1 for each pressure, all at room temperature) are the output files encoding the crystal structure. The .lst files give the lists of reflections recorded in the single-crystal x-ray diffraction measurements. Checkcif reports are the standardised reports verifying data quality and giving explanations for any issues. .cif and .lst files are named in the following manner: "7p4 kbar Exp-292_JT3_38-d08_15-7-3". The "7p4 kbar" here means 'pressure value of 7.4 kbar'. - Figure Data Exported data from each of the figures 3 to 8 presenting data in the paper. With the exception of the structural data in Fig 5, each data series in each figure is placed into a separate .dat comma-separated text file. These files can be opened in a text editor or imported into e.g. Matlab with ease. Filenames refer to the Figure, subfigure, then data series label - for instance "Figure3a - 0p9K" plots the green data in Figure 3(a) in the paper (the data taken at 0.9 K). For Figure 5, the data are tabulated in multiple columns, with headers corresponding to the data sets and their error bars shown in 5(a-i). 2024-01-01T00:00:00Z Dataset Dataset 10.82444/warw.33880072.v1 https://figshare.com/articles/dataset/Data_for_Asymmetric_phase_diagram_and_dimensional_crossover_in_a_system_of_spin-1_2_dimers_under_applied_hydrostatic_pressure/33880072 CC BY 4.0