All three compositions -L3P1N3, L2P2N3 and L1P3N3were synthesised using the sol-gel route . Stoichiometric quantities, depending on the material composition, of La(NO3)3•6H2O (Sigma Aldrich, 99.0%), Pr(NO3)3•6H2O (Sigma Aldrich, 99.99%) and Ni(NO3)2•6H2O (Sigma Aldrich, 99.0%) were dissolved in an aqueous solution of 10% (by weight) of citric acid (Sigma Aldrich, 99.99%). The solution was heated at 250 ˚C, under constant stirring for three hours, until a gel was obtained. The gel, after being decomposed in the air for 12 hours at 600 ˚C, was ground and the resultant powder was annealed for 24 hours in air at 950˚C (L1P3N3) and 1000 ˚C (L2P2N3 and L3P1N3) prior to phase determination by X-ray powder diffraction. The XRD patterns of the material were collected using a PANalytical X'Pert Pro MPD (Cu K source) and Rietveld refinement of the XRD data, performed with the GSAS/EXPGUI software package was used to confirm the phase identification. We recently reported the initial XRD studies detailing all three compositions .