Unravelling the nanoscale mechanism of polarization reversal in a HfZrO-based ferroelectric capacitor by vector piezoresponse force microscopy.

Ferroelectricity is in demand in many device concepts in electronics, energy and microsystem engineering. The performance of ferroelectrics-based devices is determined by either out-of-plane or in-plane polarization, or out-of-plane or in-plane piezoelectric strain. Real prospects for the practical implementation of innovative devices opened up after the discovery of ferroelectricity in ultrathin hafnium oxide films, due to their perfect compatibility with silicon technology.

Nanoscale Doping and Its Impact on the Ferroelectric and Piezoelectric Properties of HfZrO.

Ferroelectric hafnium oxide thin films-the most promising materials in microelectronics' non-volatile memory-exhibit both unconventional ferroelectricity and unconventional piezoelectricity. Their exact origin remains controversial, and the relationship between ferroelectric and piezoelectric properties remains unclear. We introduce a new method to investigate this issue, which consists in a local controlled modification of the ferroelectric and piezoelectric properties within a single HfZrO capacitor device through local doping and a further comparative nanoscopic analysis of the modified regions.

Diode Laser Spectrometer for Diagnostic Assessment of Exhaled Air Components.

The main requirements for a screening test are simplicity, non-invasiveness, safety of testing procedures, high processing speed, and ability to detect diseases at an early stage. A multichannel gas analyzer for assessment of exhaled air composition (diode laser spectrometer), non-invasive screening, and biomedical testing was developed on the basis of near-infrared diode lasers with fiber output. The device measures the following exhaled air components: CO, CO, CH, NH, HO, and HS.

Band Excitation Piezoresponse Force Microscopy Adapted for Weak Ferroelectrics: On-the-Fly Tuning of the Central Band Frequency.

New interest in microscopic studies of ferroelectric materials with low piezoelectric coefficient, $d_{33}^\ast$, has emerged after the discovery of ferroelectric properties in HfO2 thin films, which are the main candidate for the next generation of nonvolatile ferroelectric memory. The study of the microscopic structure of ferroelectric HfO2 capacitors is crucial to get insights into the device behavior and performance. However, a small $d_{33}^\ast$ of ferroelectric HfO2 films leads to a low piezoresponse, especially in band excitation piezoresponse force microscopy (BE-PFM).

Nanoscale Tailoring of Ferroelectricity in a Thin Dielectric Film.

New opportunities in the development and commercialization of novel photonic and electronic devices can be opened following the development of technology-compatible arbitrary-shaped ferroelectrics encapsulated in a passive environment. Here, we report and experimentally demonstrate nanoscale tailoring of ferroelectricity by an arbitrary pattern within the nonferroelectric thin film. For inducing the ferroelectric nanoregions in the nonferroelectric surrounding, we developed a technology-compatible approach of local doping of a thin (10 nm) HfO film by Ga ions right in the thin-film capacitor device focused ion beam implantation.