Assigning of this interface peak to a specific correlation is not trivial. However, the structures of crystalline zinc phosphate phases (Figure ) have been used to obtain sensible bond lengths involving O, P and Zn atoms. These suggest that the interface peak arises from a Zn•••P distance in which the Zn and P atoms are bridged via an oxygen atom. Furthermore, the difference in peak amplitudes in the mixtures and blends can be rationalised when considering the plethora of reactions that can be initiated via ball-milling. More specifically, the Zn-O-P interaction has been mechanochemically induced in the literature in which a zinc phosphate coordination polymer was synthesised by hand grinding alone. Here, we tentatively suggest that ball-milling initiates the interfacial interactions and subsequent heat treatment strengthens these interactions even further, culminating in a larger interface peak.