  Nanomagnetic oscillator is a key component for radio-frequency (RF) signal
generation in many nano-scale spintronic devices. However, the actuation
mechanisms of nanomagnetic oscillators are mostly current-based, which is
energy inefficient at nanoscale due to Joule heating. In this study, we present
a new actuation mechanism for nanomagnetic oscillator with pure voltage input
using a multiferroic structure. An AC voltage with a DC bias is applied to the
piezoelectric substrate, and steady perpendicular magnetic oscillation is
achieved in the attached Ni disk when the frequency of the voltage matches the
ferromagnetic resonance (FMR) of the Ni disk. The FMR can be tuned by simply
changing the voltage bias, therefore, the oscillation frequency has a wide
range. A systematic simulation study is conducted to investigate the impact of
the voltage amplitude, frequency, waveform, as well as the thickness of the
magnet on the magnetic oscillation. This opens new possibilities of designing
energy efficient nanomagnetic oscillators using multiferroics that have large
amplitude and wide frequency range.
