Study of Hardening and Softening Characteristics in A-site Acceptor- and Donor-Doped 0.93Bi0.5Na0.5TiO3-0.07BaTiO3 Lead-Free Piezoceramics

Abstract

The still unclear and inconsistent doping effects, particularly the effects of acceptor (hard) doping in BNT-based lead-free ceramics compared to PZT, are one of the reasons that have limited their usage in commercial applications. In this study, the effects of A-site Ag+ acceptor doping on the structure, dielectric, electrical conductivity and electromechanical properties of lead-free 0.93BNT-0.07BT (BNBT) ceramics (Ag100x, x=0.01-0.04) were systematically investigated. Rietveld refinement analysis revealed the coexistence of rhombohedral (R3c) and tetragonal (P4bm) phases, with an increase in P4bm phase fraction as x increased. An increasing of x value led to a significant decrease in resistivity (~1 order of magnitude) and a change from homogeneous to heterogeneous electrical microstructure. Furthermore, Ag+ doping has been found to exhibit amphoteric effects on the electromechanical properties. At low doping levels (x=0.01-0.02), the materials displayed a constricted P-E loop with a significant decrease in coercive field (Ec), and increases in dielectric loss (tan delta), permittivity (epsilon r), and piezoelectric coefficient (d33), which resemble softening characteristics. In contrast, for higher doping level (x=0.03-0.04), a square P-E loop with a substantial increase Ec and a decrease in Pr, Pm was detected, along with a decrease in tan delta, epsilon r, and d33, which are all the indication of hardening characteristics in PZT. These findings provide a better understanding of the effects of A-site acceptor doping on BNT-based ceramics, which can aid a more reliable modification of these materials for real-world applications.

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Document Details

Document Type
Technical Report
Publication Date
Mar 29, 2023
Accession Number
AD1211596

Entities

People

  • David P. Cann
  • Pathit Premwichit
  • Ryan R. Mcquade
  • Sasipohn Prasertpalichat
  • Theeranun Siritanon

Organizations

  • Faculty of Medical Science, Naresuan University
  • Oregon State University
  • Suranaree University of Technology

Tags

DTIC Thesaurus Topics

  • Charge Carriers
  • Chemical Synthesis
  • Chemistry
  • Crystal Structure
  • Crystals
  • Dielectric Permittivity
  • Dielectric Properties
  • Domain Walls
  • Electric Fields
  • Electrical Conductivity
  • Electrical Properties
  • Electrons
  • Materials Science
  • Piezoceramics
  • Solid Solutions
  • Titanates
  • Transition Temperature

Fields of Study

  • Materials science

Readers

  • Materials Science and Engineering.
  • Powder metallurgy of Titanium alloys.
  • Semiconductor Device Technology

Technology Areas

  • Microelectronics
  • Microelectronics - Graphene