Dr. Ashley Black graduated with a thesis in "New oxynitride materials with luminescent, magnetic and catalytic properties" in the Solid State Chemistry group, supervised by Dr. Amparo Fuertes.
He defended his thesis this last 16th June. The PhD committee were Regino Saez Puche, Universidad Complutense de Madrid, Spain (President), José Peral, Universitat Autònoma de Barcelona, Spain (Secretary), Ralf Riedel, Darmstadt University of Technology, Germany (Vocal).
Abstract: In this thesis we describe the synthesis and luminescent properties of a new family of phosphors for white LED technology, based on orthosilicate β-K2SO4 structure. In particular, the oxynitridosilicates LaMSiO3N (M = Sr, Ba) and Sr2-xLaxSiO4-xNx (0≤x<1) that when doped with Eu2+ or Ce3+ show tuneable luminescence between 500 and 750 nm. In the second section, we extend the AB(O,N)3 oxynitride perovskites to the transition metals Cr and Hf. The antiferromagnetic behaviour of Cr3+/Cr4+ in LnCrO3-xNx (Ln = La, Pr, Nd; 0 ≤ x ≤ 0.59) perovskites.