The composition-structure-property relationships of several important oxides are reported. The effect of sintering atmosphere, cooling rate and post annealing in N2 on the composition, B-site cation ordering, electrical conductivity and microwave dielectric loss of BCN ceramics have been investigated. X-ray Diffraction (XRD), Transmission Electron Microscopy (TEM) and Raman Spectroscopy (RS) results confirm that a slow cooling rate from the sintering temperature and/or post annealing below the order-disorder phase transition temperature increases the degree of B-site cation 1:2 ordering regardless of the oxygen partial pressure (pOj) of the sintering and/or annealing atmosphere.