Piezoresponse force microscopy and electron backscattering diffraction of 90° ferroelectric twins in BaTiO3 positive temperature co-efficient thermistors. (25th April 2020)

• Record Type: Journal Article
• Authors: Karimi-Jafari, M.; Stapleton, A.; Guo, Y.; Kowal, K.; Chovan, D.; Kailas, L.; Gandhi, A.; O'Sullivan, K.; Maher, A.; Tofail, S. A. M.; Haq, E. U.
• Is Part Of: Ferroelectrics. Volume 559(2020)
• Page Start: 109
• Page End: 119
• Publication Date: 2020-04-25
• Subjects: Barium titanate -- thermistors -- piezoelectricity -- ferroelectric domains -- piezoresponse force microscopy; Ferroelectricity -- Periodicals; Ferroelectric crystals -- Periodicals; 537
• DOI: 10.1080/00150193.2020.1722012
• Languages: English
• ISSNs: 0015-0193

Abstract

Abstract: The positive temperature co-efficient (PTC) of resistivity in BaTiO3 is a grain boundary effect, where the resistivity increases by several orders of magnitude near the transition temperature from ferroelectric (tetragonal) to paraelectric (cubic) phase. We combine electron backscatter diffraction (EBSD) and piezoresponse force microscopy (PFM) to investigate the crystallographic orientation, topography, and intergranular polarization in polycrystalline PTC BaTiO3 ceramics leading to PTC effect. EBSD study showed that while macroscale BaTiO3 displayed no overall preferential crystallographic orientation, individual grains had preferred orientations at a localized level. Twinning patterns were revealed by EBSD and PFM images showing classical 90° ferroelectric domain patterns.