Further analysis of the compaction

Further analysis of the compaction data reveal that the strain of the compacts (e) is found to follow for all investigated pressures a power relation with respect to the elapsed time (t) of the form: e ¼ tn, where the exponent n varies between 1 and 1/3 within the first 60 s, followed by a slow down of the densification process at longer times (Fig. 3g). In classical liquid-assisted sintering models22,34, an exponent of 1 is expected when mass transport is dominated by viscous flow-induced particle rearrangement at an early densification stage. This is typically followed by a dissolution–precipitation process at the contact point between grains, which results in an exponent of 1/3 for the strain-time relation. While further studies are need to elucidate the dominant mass transport processes operating at different timescales and pressures, the observation of similar exponents in our timedependent strain data suggest that liquid-assisted densification mechanisms that resemble classical sintering processes seem to govern the sintering of the vaterite compounds investigated in this work.