Room-temperature multiferroicity in GaFeO₃ thin film grown on (100)Si substrate

Room-temperature magnetoelectric multiferroicity has been observed in c-axis oriented GaFeO₃ thin films (space group $Pna21$⁠), grown on economic and technologically important (100)Si substrates by a pulsed laser deposition technique. Structural analysis and comprehensive mapping of the Ga:Fe ratio across a length scale range of 10⁴ reveals coexistence of epitaxial and chemical strain. It induces formation of finer magnetic domains and large magnetoelectric coupling—a decrease in remanent polarization by $∼21$% under $∼50$ kOe. Magnetic force microscopy reveals the presence of both finer (⁠$<100$ nm) and coarser (⁠$∼2$ $μ$m) magnetic domains. Strong multiferroicity in epitaxial GaFeO₃ thin films, grown on a (100)Si substrate, brighten the prospect of their integration with Si-based electronics and could pave the way for development of economic and more efficient electromechanical, electrooptic, or magnetoelectric sensor devices.