Happy Thanksgiving to all our friends in the USA and Canada!
Enjoy the time with family and friends and don’t forget to visit us @NanoAndMore USA booth no. 311 @Materials_MRS MRS Fall 2022 after the holidays if you are planning to travel to Boston to participate in the conference. We’re looking forward to seeing you there.
Nano-piezoelectric materials such as 1D piezoelectric nanofibers, nanowires, and nanobelts have attracted a lot of research interest in recent years. *
Because of their active property that can transform strain energy into electricity, 1D piezoelectric nano-materials can be building blocks for nano-generators, strain sensors, acoustic sensors, force sensors, biosensors, self-powered drug delivery systems, piezoelectric transistors and other intelligent systems. *
The most important property of these active materials is their ability to convert mechanical energy into electrical energy and vice versa. *
Therefore, researchers started developing nano-sized piezoelectric materials in hope of achieving better piezoelectric properties. *
The characterization of these piezoelectric properties, especially measuring the piezoelectric strain coefficients, remains a challenge. *
The Atomic Force Microscopy (AFM)-based method to directly measure nano-materials’ piezoelectric strain coefficients is widely used.
However, several factors such as the extremely small piezoelectric deformation, the influence from the parasitic electrostatic force, and the environmental noise can make the measurement results questionable. *
In the article “Piezoelectric property of PZT nanofibers characterized by resonant piezo-force microscopy” Guitao Zhang, Xi Chen, Weihe Xu, Wei-Dong Yao, and Yong Shi address these issues by introducing a resonant piezo-force microscopy method and describing how it was used to accurately measure the piezoelectric deformation from 1D piezoelectric nanofibers. *
During the measurement the AFM tip was brought into contact with the piezoelectric sample and set to work close to the AFM tip’s first resonant frequency. *
The AFM probe used in this test was a platinum iridium coated NanoWorld Arrow-CONTPt (typical force constant 0.2 N/m, typical resonant frequency 14 KHz. The PtIr coating makes the AFM tip conductive and at the same time enhances the laser reflection from the detector facing side of the AFM cantilever to the photodetector. *
A lock-in amplifier was used to pick up the sample’s deformation signal at the testing frequency. By using this technique, the piezoelectric strain constant d33 of the Lead Zirconate Titanate (PZT) nanofiber with a diameter of 76 nm was measured. The result showed that d33 of this PZT nanofiber was around 387 pm/V. Meanwhile, by tracking the piezoelectric deformation phase image, domain structures inside PZT nanofibers were identified. *
*Guitao Zhang, Xi Chen, Weihe Xu, Wei-Dong Yao and Yong Shi
Piezoelectric property of PZT nanofibers characterized by resonant piezo-force microscopy
AIP Advances 12, 035203 (2022)
DOI: https://doi.org/10.1063/5.0081109
The article “Piezoelectric property of PZT nanofibers characterized by resonant piezo-force microscopy” by Guitao Zhang, Xi Chen, Weihe Xu, Wei-Dong Yao and Yong Shi is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. The images or other third party material in this article are included in the article’s Creative Commons license, unless indicated otherwise in a credit line to the material. If material is not included in the article’s Creative Commons license and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this license, visit https://creativecommons.org/licenses/by/4.0/.
HfO2-based films are important materials used in broad range of electronic applications from high-performance transistors and memory cells, to thermoelectric and energy harvesting elements. *
In the article “Impact of annealing on electric and elastic properties of 10-nm Hf0.5Zr0.5O2 films prepared on Si by sputtering” Leonid Bolotov, Shinji Migita, Ryouta Fujio, Manabu Ishimaru, Shogo Hatayama and Noriyuki Uchida described how they used scanning probe methods to make nanoscale comparison of chemical composition, surface morphology, the elastic modulus and the surface potential of bare 10-nm thick Hf0.5Zr0.5O2 films prepared on Si by a carbon-free sputtering process. *
NanoWorld conductive platinum iridium5 coated Pointprobe® EFM AFM probes were used for the electrostatic force microscopy (EFM). *
The composition mapping confirmed uniform distribution of Hf and Zr in the film along wafer size. Suppression of the monoclinic phase in films annealed at 600 – 800 °C had strong impact on spatial variations of film properties. Small surface roughness, large electric domain sizes (50–200 nm at 700 °C) and small fluctuations of the surface potential (40–50 meV) in Si coated with the films are appealing for gate-stack applications. Films annealed at 600-700 °C showed the elastic modulus of about 169 GPa and the ferroelectric polarization reversal at a field of ~1 MV/cm as observed by nanoscale poling with a Pt-coated scanning probe. In contrast, properties of films annealing at 800 °C were affected by growth of thick interfacial oxide layer. *
The nanoscale approach presented in the article is beneficial in optimizing of physical and mechanical properties of thin dielectric films. *
*Leonid Bolotov, Shinji Migita, Ryouta Fujio, Manabu Ishimaru, Shogo Hatayama and Noriyuki Uchida
Impact of annealing on electric and elastic properties of 10-nm Hf0.5Zr0.5O2 films prepared on Si by sputtering
Microelectronic Engineering, Volume 258, 1 April 2022, 111770
DOI: https://doi.org/10.1016/j.mee.2022.111770
Open Access The article “Impact of annealing on electric and elastic properties of 10-nm Hf0.5Zr0.5O2 films prepared on Si by sputtering” by Leonid Bolotov, Shinji Migita, Ryouta Fujio, Manabu Ishimaru, Shogo Hatayama and Noriyuki Uchida is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. The images or other third party material in this article are included in the article’s Creative Commons license, unless indicated otherwise in a credit line to the material. If material is not included in the article’s Creative Commons license and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this license, visit http://creativecommons.org/licenses/by/4.0/.