, a relatively minor or mild heat treatment (i.e., heating of the material to a temperature of no more than about 000xc0x0 C., e.g., a temperature of approximately 000-000xc0x0 C. and holding the heated material at that temperature for a duration of at least approximately 0 minutes) of the material resulting upon such spray drying, may be desired or required in order to ensure or complete conversion of the transition metal species to the desired transition metal diammine dinitrate and such has been found to remain in a stable form. 