This is generally based on the synthesis of new f-block complexes, structural and bonding properties and their uses in different fields including in nuclear fuel cycles, energy and single molecule magnets.

[5] Upon graduation, he continued to read for his Doctor of Philosophy degree with Prof. Jones on Investigations into the Reactivity of an Anionic Gallium(I) N-Heterocyclic Carbene Analogue and successfully gained his PhD in 2007.

[5] Mill's research is generally on lanthanide and Actinide chemistry and is specifically based on the synthesis of new f-block complexes, structural and bonding properties and their uses in different fields including in nuclear fuel cycles, energy and single molecule magnets.

[12] In 2016, Mills also confirmed the capability to use pulsed EPR spectroscopy to measure the covalency of actinide complexes in research in collaboration with Floriana Tuna and Professor Eric Mcinnes at the University of Manchester.

[13] Prior to this research, the extent of covalency in actinide complexes was less understood as this nature of bonding was not studied due to limited technology and methods of experimentation at the time.