3 years ago

Length-scale dependent average structures, piezoelectricity enhancement and depolarization mechanisms in a non-MPB high-performance piezoelectric alloy system PbTiO3-Bi(Zr1/2Ni1/2)O3.

Rajeev Ranjan, Rishikesh Pandey, Mulualem Abebe, Shekhar Tyagi, Dipak Kumar Khatua, Bastola Narayan, Vasant Sathe

There is a general perception that large piezoelectric response in ferroelectric alloys requires tuning the system towards a morphotropic phase boundary (MPB), i.e., a composition driven inter-ferroelectric instability. Here we show that high piezoelectric response can be realized even in non-MPB alloy systems. This is demonstrated on (1-x)PbTiO3-(x)Bi(Zr0.5Ni0.5)O3 (PT-BNZ) by a comprehensive study involving electric-field and temperature dependent XRD, Raman spectroscopy, dielectric, piezoelectric and high field electrostrain measurements. We found that poling-field irreversibly suppresses the cubic-like phase at room temperature. Based on our results, we argue that that which appears as MPB, comprising of tetragonal and cubic-like phases on the global scale, is not so actually. The large piezoresponse is due to coexistence of tetragonal regions of long and short-range coherence. The PT-BNZ system is therefore qualitatively different from the conventional MPB systems such as PZT, PMN-PT, and PbTiO3-BiScO3, etc., which exhibits coexisting tetragonal and rhombohedral/monoclinic phases in thermodynamic equilibrium. In the absence of inter-ferroelectric instability as a phenomenon, field induced polarization-rotation and inter-ferroelectric transformation are no longer plausible mechanisms to explain the large piezoelectric response in PT-BNZ. The large piezoelectricity is primarily due to enhanced mobility of the tetragonal domain walls enabled by domain miniaturization. Our study proves that attainment of large piezoelectricity does not require inter-ferroelectric instability as a necessary criterion.

Publisher URL: http://arxiv.org/abs/1801.03310

DOI: arXiv:1801.03310v1

You might also like
Never Miss Important Research

Researcher is an app designed by academics, for academics. Create a personalised feed in two minutes.
Choose from over 15,000 academics journals covering ten research areas then let Researcher deliver you papers tailored to your interests each day.

  • Download from Google Play
  • Download from App Store
  • Download from AppInChina

Researcher displays publicly available abstracts and doesn’t host any full article content. If the content is open access, we will direct clicks from the abstracts to the publisher website and display the PDF copy on our platform. Clicks to view the full text will be directed to the publisher website, where only users with subscriptions or access through their institution are able to view the full article.