RF voltage-controlled magnetization switching in a nano-disk

Nanomagnetic oscillators are key components for radio-frequency (RF) signal generation in nanoscale devices. However, these oscillators are primarily electric current-based, which is energy inefficient at the nanoscale due to ohmic losses. In this study, we present an actuation mechanism for magnetization switching using a multiferroic structure that relies on an RF voltage input instead of electrical current. An AC voltage with a DC bias is applied to the piezoelectric substrate and the magnetic nanodisk with perpendicular magnetic anisotropy that is attached onto the substrate, which can achieve steady magnetic oscillation when the driven voltage is at ferromagnetic resonance (FMR) of the nanodisk. Changing the DC bias changes the magnetic anisotropy of the magnetoelastic nanodisk, hence changes the FMR and oscillation frequency. The frequency modulation is quantified using the Kittel equation. Parametric studies are conducted to investigate the influence of voltage amplitude, frequency, waveform, and the thickness of the magnetoelastic nanodisk. This multiferroic approach opens possibilities for designing energy efficient nanomagnetic oscillators that have both large amplitude and broad frequency range. Published under license by AIP Publishing.