Monolithic integration of room-temperature multifunctional BaTiO_sub3sub_-CoFe_sub2sub_O_sub4sub_ epitaxial heterostructures on Si(001)
Mateusz Scigaj, Nico Dix, Jaume Gázquez, María Varela, Ignasi Fina, Neus Domingo, Gervasi Herranz, Vassil Skumryev, Josep Fontcuberta & Florencio Sánchez. Scientific Reports 6, Article number: 31870 (2016). doi:10.1038/srep31870
The multifunctional (ferromagnetic and ferroelectric) response at room temperature that is elusive in single phase multiferroic materials can be achieved in a proper combination of ferroelectric perovskites and ferrimagnetic spinel oxides in horizontal heterostructures. In this work, lead-free CoFe2O4/BaTiO3 bilayers are integrated with Si(001) using LaNiO3/CeO2/YSZ as a tri-layer buffer. They present structural and functional properties close to those achieved on perovskite substrates: the bilayers are fully epitaxial with extremely flat surface, and exhibit robust ferromagnetism and ferroelectricity at room temperature.