Fig. 5
Low temperature and low field magnetic relaxation. a Magnetic relaxation rate measured by DC magnetometry (note the log-log scale) for 1 (purple circles), 1a (green circles) and 1b (light blue circles) at 2 K; black lines are best fits to \(\tau _{\mathrm{QTM}}^{ - 1} = {{AH}}^{ - i}\) with i = 2.9(2), A1 = 5(1) × 103, A1a = 34(3) and A1b = 2.4(4) s−1 Oei. b Magnetic relaxation rate measured by DC magnetometry (note the log-lin scale) for 1 at 526(1) (purple circles) and for 1a at 79(1) (green circles); black line is a best fit to \(\tau _{\mathrm{QTM}}^{ - 1} = {{A{\mathrm e}}}^{jT}\) with j = 0.9(2) K−1 and A = 8(5) × 10−6 s−1. c Magnetic relaxation rate measured by DC magnetometry (note the log-lin scale) for 1 at 86(1) (purple circles), 126(1) (green circles) and 176(10) Oe (light blue circles); solid lines are a guide for the eye, there are two data points at 2, 3, and 4 K for the 176(10) Oe data, giving the appearance of a zig-zag line. Error bars are mostly within the data points
