In time domain MR analysis, an instrument with a short deadtime must be utilized to capture the short T2* component found in solid materials. A 4.7 T vertical-bore superconducting magnet (Cryomagnetics) and a Redstone HF NMR spectrometer console (Tecmag) equipped with a Doty DS1-874 1 H RF probe (Doty Scientific) were utilized. Samples were either transferred to a glass vial for analysis or kept in the lab-made Teflon jar used during milling (see Supporting Material (SM), section S1). A large amount of sample (gram scale) was employed to increase sensitivity and to ensure the sample signal dominates over background signal from the probe.