Magnetization measurements were performed between 0-7 T at 2 K, 4 K and (for Yb samples) 10 K. For Sm samples, points were recorded at 0.25 T steps between 0-1 T, 0.5 T steps between 1-2 T and 1 T steps between 2-7 T. For Tm and Yb samples, points were recorded at 0.2 T steps between 0-1 T and 0.5 T steps between 1-7 T, with 10 min waits at each field point. Hysteresis curves were recorded for 2-Yb and 4-Yb at 2 K and between ± 7 T. The sweep rates were as follows: 22.0 Oe/s for 0 < |H| < 1 T, 51.9 Oe/s for 1 < |H| < 2 T and 90.6 Oe/s for 2 < |H| < 7 T.