a Magnetic susceptibility, χ(T), in both zero-field-cooled (ZFC) and field-cooled (FC) sweeps. Inset shows χT. Black solid line shows the high-temperature CW fit. b Magnetization vs applied field at 2 K. Inset shows high-field magnetization data at 4 K. c Zero-field specific heat as a function of temperature. Inset shows C/T at different applied fields.