Mixed-metal tert-butoxide, [CoGa
2
(O
t
Bu)
8
], was employed in the chemical vapor deposition (CVD) and sol-gel processes to obtain thin films and nanoparticles of spinel CoGa
2
O
4
phase, respectively. The appropriate Co:Ga ratio and intact vaporization (115-120 °C / 10
-2
Torr) of the molecular source produced crystalline deposits of CoGa
2
O
4
at relatively low temperatures (~ 500 °C). A clean transformation of the heterometal precursor in spinel oxide of definite composition was supported by TG/DTA analysis that showed no weight loss above 470 °C. The SEM images of CoGa
2
O
4
films showed homogeneous morphology and dense microstructure constituted by nanometric grains (
d
, ~ 35 nm). Hydrolytic decomposition of the precursor produced gels that upon heat-treatment (400-1200 °C) formed nanoscaled spinel. For comparison, CoGa
2
O
4
was also prepared by complexing Co
2+
and Ga
3+
ions with glycolate ligands, significant agglomeration effect, broader size dispersion and amorphous domains were observed indicating that low-temperature synthesis of monophasic materials following conventional chemical approaches is hampered by thermodynamic impediments. The UV/Vis spectra of CoGa
2
O
4
particles exhibit characteristic peaks corresponding to
4
A
2
(F)
à
4
T
1
(P) transition in the divalent cobalt cation. The magnetization data of the CoGa
2
O
4
nanoparticles showed as expected an antiferromagentic behavior.