Silica-coated iron nickel (FeNi@SiO2) particles
have
attracted significant attention because of their potential applications
in electronic devices. In this work, submicron-sized spherical FeNi@SiO2 particles with precisely controllable shell thickness were
successfully synthesized for the first time using a swirler connector-assisted
spray pyrolysis system, comprising a preheater, specific connector,
and main heater. The results indicated that the thickness of the SiO2 shell can be tuned from 3 to 23 nm by adjusting the parameter
conditions (i.e., preheater temperature, SiO2 supplied
amount). Furthermore, our fabrication method consistently yielded
a high coating ratio of more than 94%, indicating an excellent quality
of the synthesized particles. Especially, to gain an in-depth understanding
of the particle formation process of the FeNi@SiO2 particles,
a plausible mechanism was also investigated. These findings highlight
the importance of controlling the preheater and SiO2 supplied
amount to obtain FeNi@SiO2 particles with desirable morphology
and high coating quality.