Fig. 4: Uniaxial pressure dependence of the magnetic order and correlations.
Elastic θ/2θ scans of \({\sigma }_{z}^{\mathrm{SF}\,}\) across a Q1 = (1, 0, 1) and b Q2 = (1, 0, 3) at different temperatures and P = 20 MPa. The data are collected on BT-7 using final neutron energy of 14.7 meV with instrumental energy resolution of about 1.3 meV. Similar scans of \({\sigma }_{z}^{\mathrm{SF}\,}\) are discussed in Supplementary information for additional data and analysis. \({\sigma }_{y}^{\mathrm{SF}\,}\) was unavailable at the time of this experiment. c FWHM of the elastic (1, 0, 1) and (1, 0, 3) scans across TN/Ts. d Temperature dependence of I101/I103 ∝ (0.16Ma + 0.84Mc)/(0.63Ma + 0.37Mc). e Temperature dependence of I101/I103 at P ≈ 0 and ~ 45 MPa uniaxial pressure obtained using in-situ uniaxial pressure device with unpolarized neutrons on BT-7. f Pressure dependence of I101/I103 (red symbols, left axis) and Mc/Ma (green symbols, right axis) at T ~ 142 K. The data points for P = 0 and 45 MPa were measured with unpolarized neutron scattering. The data points for P = 20 Mpa were measured with polarized mode with the open (solid) symbols obtained from \({\sigma }_{z}^{\mathrm{SF}\,}\) (\({\sigma }_{x}^{\mathrm{SF}\,}\)). The black dashed curve is a guide to the eye for the data points. unpol. denotes unpolarized neutron scattering measurements. The vertical error bars in (a, b, d, e) represent statistical errors of 1 standard deviation. The error bars in (c) are estimated errors from fits to magnetic Bragg peak widths. The error bars in (f) are our estimated errors from fits to magnetic order parameters and applied uniaxial pressure.
