Waveform measurements as a function of frequency and temperature were made using the same sample setup and temperatures as the DC decays. The same method developed by Hilgar et al. was used, but with a sweep rate of 700 Oe/s and each square-wave period repeated five times for all temperatures apart from the 36 µHz measurement at 4 K, where 3 square-wave periods were used. Between 7 and 11 unique frequencies of the driving square-wave magnetic field were used at each temperature. The magnet was reset before the measurements were performed to ensure that the superconducting magnet did not contain residual fields. In-and out-of-phase susceptibility components were extracted from the data using the Super package in Matlab. Fitting of the frequency-dependence of the susceptibility components was performed in Mathematica. Fitting of the relaxation profiles was performed in CC-FIT2. 4 Results and discussion