Suchergebnisse

We demonstrate the abilities of various SEM techniques for domain imaging in PMN-PT crystals with different compositions. It is shown that the imaging of the chemically etched relief is limited by its destructivity and potential contrast - by low resolution and contrast instability. The optimal parameters of the imaging by backscattered electron channelling allow obtaining the high-resolution domain imaging in PMN-PT crystals. The domain structure change as a result of the phase transition are imaged. The correlation between the images of the surface domain structure obtained by scanning electron microscopy and piezoresponse force microscopy is demonstrated. © 2018 Institute of Physics Publishing. All rights reserved. ; The equipment of the Ural Centre for Shared Use "Modern Nanotechnology" Ural Federal University has been used. The research was made possible by RFBR (grant 17-52-80116-BRICS_a) and state task of Ministry of education and science of the Russian Federation (No. 3.4993.2017/6.7). The work was partially supported by Government of the Russian Federation (Act 211, Agreement 02.A03.21.0006). ; et al.;NT-MDT Spectrum Instruments;Ostec-ArtTool Ltd.;Promenergolab LLC;Russian Foundation for Basic Research;Taylor and Francis Group

We have studied the influence of initial domain structure on piezoelectric and dielectric properties of Sr 0.61 Ba 0.39 Nb 2 O 6 single crystals slightly doped with Ce and Ni. Initial domain structure was created by zero-field cooling, in-field cooling, and partial switching. The difference in the frequency dependences of macroscopic piezoelectric response and temperature dependences of dielectric permittivity for various initial domain structures was revealed. © 2018 Institute of Physics Publishing. All rights reserved. ; Equipment of the Ural Centre for Shared Use "Modern nanotechnology" Ural Federal University was used. The research was made possible by Russian Foundation of Basic Research (project № 16-02- 00821-а) and state task of Ministry of education and science of the Russian Federation (No. 3.4993.2017/6.7). The work was partially supported by Government of the Russian Federation (act 211, agreement 02.A03.21.0006). Part of this work was developed within the scope of the project CICECO-Aveiro Institute of Materials, POCI-01-0145-FEDER-007679 (FCT Ref. UID /CTM /50011/2013), financed by national funds through the FCT/MEC and when appropriate co-financed by FEDER under the PT2020 Partnership Agreement. ; et al.;NT-MDT Spectrum Instruments;Ostec-ArtTool Ltd.;Promenergolab LLC;Russian Foundation for Basic Research;Taylor and Francis Group

We have studied a dense domain structure (DDS) appearing during polarization reversal in rhombohedral (111)-cut lead magnesium niobate-lead titanate single crystals. The complicated shape of the switching current was explained by means of non-uniform motion of the boundary between the DDS and c-domains using comparative analysis of the optical current and kinetic map. 2D-vector piezoresponse force microscopy revealed that DDS represented needle-like a-domains inside the a-domains with different vertical orientations of spontaneous polarization. © 2020 Author(s). ; The equipment of the Ural Center for Shared Use "Modern Nanotechnology" UrFU was used. This work has been supported in part by the Ministry of Science and Higher Education of the Russian Federation under Project No. 3.9534.2017/8.9, by the Government of the Russian Federation (Act 211, Agreement No. 02.180 A03.21.0006) and by RFBR (Grant No. 17-52-80116-BRICS_a). This work was supported by the NSFC projects (Grant No. 51761145024), Shaan Xi province Project (Nos. 2017 ktpt-21 and 2018TD-024), and the 111 Project under Grant No. B14040.

Ferroelectric materials based on lead zirconate titanate (PZT) are widely used as sensors and actuators because of their strong piezoelectric activity. However, their application is limited because of the high processing temperature, brittleness, lack of conformal deposition, and a limited possibility to be integrated with the microelectromechanical systems (MEMS). Recent studies on the piezoelectricity in the 2-D materials have demonstrated their potential in these applications, essentially due to their flexibility and integrability with the MEMS. In this work, we deposited a few layer graphene (FLG) on the amorphous oxidized Si3N4 membranes and studied their piezoelectric response by sensitive laser interferometry and rigorous finite-element modeling (FEM) analysis. Modal analysis by FEM and comparison with the experimental results show that the driving force for the piezoelectric-like response can be a polar interface layer formed between the residual oxygen in Si3N4 and the FLG. The response was about 14 nm/V at resonance and could be further enhanced by adjusting the geometry of the device. These phenomena are fully consistent with the earlier piezoresponse force microscopy (PFM) observations of the piezoelectricity of the graphene on SiO2 and open up an avenue for using graphene-coated structures in the MEMS. © 1986-2012 IEEE. ; This work was supported in part by the Russian Foundation or Fundamental Research under Grant 16-29-14050, in part by the Ministry of Education and Science of the Russian Federation in the framework of the Increase Competitiveness Program of MISiS under Grant K2-2019-015, in part by the Project CICECO-Aveiro Institute of Materials financed by national funds through the Portuguese Foundation for Science and Technology/MCTES under Grants UIDB/50011/2020 and UIDP/50011/2020, and in part by the Center for Nanophase Materials Sciences, which is a Department of Energy Office of Science User Facility. The work was also supported by Government of the Russian Federation (Act 211, Agreement 02.A03.21.0006) and by the Ministry of Science and Higher Education of the Russian Federation (state task FEUZ-2020-0054). The equipment of the Ural Center for Shared Use "Modern nanotechnology" UrFU was used. The work of Yakov Kopelevich was supported in part by Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) and in part by the Fundação de Amparo à Pesquisa do Estado de S. Paulo (FAPESP) (Brazil).