The continuous economic demand for smaller and more efficient electronic devices creates a strong impetus for the development of novel materials with specialized and unique properties. Therefore, the combination of strategically selected materials with complementary characteristics at the nano level represents an efficient strategy to prepare multifunctional composites, which hold a huge potential for technical enhancements.
Currently, the synthesis of multifunctional composites is typically performed in situ in a single reaction, which is experimentally simple but often lacks control over the morphology and the generated byproducts. Additionally, no arbitrary selection of grain sizes, crystal phases and the arrangement of crystallites is possible. In contrast, the combination of pre-fabricated nanoparticles of two different materials represents a promising method to generate multifunctional nanocomposite thin films of a well-defined stoichiometry and structure. We devised a three-step approach to prepare multifunctional nanocomposite thin films from nanosized building blocks via liquid-phase based processes. The first step comprises the non-aqueous sol-gel synthesis of highly crystalline nanoparticles of a well-defined morphology. Second, a post-synthetic functionalization of the nanoparticles with organic surfactants is performed to achieve colloidal stability and compatibility. Finally, the functionalized nanoparticles are deposited by wet processing techniques in a controlled manner. Thus, this strategy enables the precise and effective preparation of multifunctional nanocomposite thin films with specific characteristics, such as magnetic and dielectric properties, by combination of a variety of different nanosized building blocks, e.g. magnetite or zirconia. The characterization of the nanoparticles as well as the prepared thin films is performed using a variety of analysis techniques such as X-ray diffraction, thermogravimetric analysis, imaging techniques (SEM, TEM, AFM) as well as conductivity, impedance and magnetometric measurements.