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Single crystals of BaTiO3 exhibit small switching fields and energies, but thin-film performance is considerably worse, thus precluding their use in next-generation devices. Here, we demonstrate high-quality BaTiO3 thin films with nearly bulk-like properties. Thickness scaling provides access to the coercive voltages (<100 mV) and fields (<10 kV cm−1) required for future applications and results in a switching energy of <2 J cm−3 (corresponding to <2 aJ per bit in a 10 × 10 × 10 nm3 device). While reduction in film thickness reduces coercive voltage, it does so at the expense of remanent polarization. Depolarization fields impact polar state stability in thicker films but fortunately suppress the coercive field, thus driving a deviation from Janovec–Kay–Dunn scaling and enabling a constant coercive field for films <150 nm in thickness. Switching studies reveal fast speeds (switching times of ~2 ns for 25-nm-thick films with 5-µm-diameter capacitors) and a pathway to subnanosecond switching. Finally, integration of BaTiO3 thin films onto silicon substrates is shown. We also discuss what remains to be demonstrated to enable the use of these materials for next-generation devices.

Abstract Magnetostrictive materials transduce magnetic and mechanical energies and when combined with piezoelectric elements, evoke magnetoelectric transduction for high-sensitivity magnetic field sensors and energy-efficient beyond-CMOS technologies. The dearth of ductile, rare-earth-free materials with high magnetostrictive coefficients motivates the discovery of superior materials. Fe 1− x Ga x alloys are amongst the highest performing rare-earth-free magnetostrictive materials; however, magnetostriction becomes sharply suppressed beyond x  = 19% due to the formation of a parasitic ordered intermetallic phase. Here, we harness epitaxy to extend the stability of the BCC Fe 1− x Ga x alloy to gallium compositions as high as x  = 30% and in so doing dramatically boost the magnetostriction by as much as 10x relative to the bulk and 2x larger than canonical rare-earth based magnetostrictors. A Fe 1− x Ga x − [Pb(Mg 1/3 Nb 2/3 )O 3 ] 0.7 −[PbTiO 3 ] 0.3 (PMN-PT) composite magnetoelectric shows robust 90° electrical switching of magnetic anisotropy and a converse magnetoelectric coefficient of 2.0 × 10 −5  s m −1 . When optimally scaled, this high coefficient implies stable switching at ~80 aJ per bit.

A Verilog-A based model for the magneto-electric field effect transistor (MEFET) device is implemented and a variety of logic functions based on this device are proposed. These models are used to capture energy consumption and delay per switching event and to benchmark the MEFET with respect to CMOS. Single-source MEFET devices can be used for conventional logic gates like NAND, NOR, inverter and buffer and more complex circuits like the full adder. The dual source MEFET is an enhanced version of the MEFET device which functions like a spin multiplexer (spin-MUXer). Circuits using MEFETs require fewer components than CMOS to generate the same logic operation. These devices display a high on-off ratio., unlike many magneto-electric devices., and they operate at very low voltages., resulting in lower switching energy. Benchmarking results show that these devices perform better in terms of energy and delay., for implementing more complex functions., than the basic logic gates.