Reverse microemulsion-mediated synthesis of various inorganic and organic nanoparticles is of interest for a variety of applications. Mixtures of commercially available polyethoxylated alcohols and linear alcohols can be employed to stabilize reverse microemulsions suitable for such use. The phase behavior, Electrical conductivity, and stability of the water/isooctane and water/cyclohexane microemulsion systems stabilized by a mixture of Neodol 91-6 nonionic surfactants and l-pentanol are presented in this paper. Quasi-elastic light scattering and small-angle neutron scattering were employed to characterize the aggregation state and morphology of the aqueous and oil phases in these reverse microemulsions. Barium hexaaluminate, a complex oxide of interest for catalytic applications, was successfully synthesized via sol-gel processing in the resulting reverse microemulsion media. The recovered inorganic nanoparticles exhibited morphologies characteristic of the aqueous phase in the reverse microemulsion systems.