Publications by authors named "A Gruverman"
Negative capacitance (NC) effects in ferroelectrics can potentially break fundamental limits of power dissipation known as "Boltzmann tyranny." However, the origin of transient NC of ferroelectrics, which is attributed to two different mechanisms involving free-energy landscape and nucleation, is under intense debate. Here, we report the coexistence of transient NC and an S-shaped anomaly during the switching of ferroelectric hexagonal ferrites capacitor in an RC circuit.
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- Strong coupling between polarization and strain in ferroelectric complex oxides allows for significant tuning of their properties, particularly demonstrated in KNbO thin films.
- Applying biaxial strain can drastically increase the Curie temperature, with predictions indicating it could exceed 1325 K under certain conditions.
- Enhanced properties such as a 46% increase in remanent polarization and a 200% boost in optical second harmonic generation coefficients make lead-free KNbO a promising candidate for high-temperature ferroelectric memory and quantum computing applications.
Ferroelectric domain walls are a rich source of emergent electronic properties and unusual polar order. Recent studies show that the configuration of ferroelectric walls can go well beyond the conventional Ising-type structure. Néel-, Bloch-, and vortex-like polar patterns have been observed, displaying strong similarities with the spin textures at magnetic domain walls.
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- Hafnia-based ferroelectric (FE) thin films are gaining attention for use in semiconductor memories, yet there is still limited understanding of how their properties change with size and thickness.
- Research demonstrates that 4 nm-thick HfZrO (HZO) capacitors can exhibit excellent ferroelectricity and durability in very small capacitor sizes (65 nm × 45 nm).
- The study highlights that while these capacitors can operate at low voltages with high endurance, fatigue issues are present, and the bottom electrode significantly influences the ferroelectric performance with scaling effects.
Ferroelectric wurtzite-type aluminum scandium nitride (AlScN) presents unique properties that can enhance the performance of non-volatile memory technologies. The realization of the full potential of AlScN requires a comprehensive understanding of the mechanism of polarization reversal and domain structure dynamics involved in the ferroelectric switching process. In this work, transient current integration measurements performed by a pulse switching method are combined with domain imaging by piezoresponse force microscopy (PFM) to investigate the kinetics of domain nucleation and wall motion during polarization reversal in AlScN capacitors.
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