Dielectric Study at Microwave Frequencies of Phase Transitions in Multiferroic Ceramics

Author(s)

Fraygola, B. ; Coelho, Adelino A. ; Eiras, J. A.

• Document type: Journal article
• Source: MATERIALS RESEARCH-IBERO-AMERICAN JOURNAL OF MATERIALS; v. 16, n. 5, p. 6-pg., 2013-09-01.

Abstract

Multiferroic ceramic solid solutions between the ferroelectric relaxor Pb(Fe2/3W1/3)O-3 (PFW) and "normal" ferroelectric PbTiO3 (PT) - PFW-PT have been synthesized by a modified B-site precursor method and characterized by microwave dielectric measurements. A dielectric dispersion occurring in the frequency range of 100MHz-3GHz and in a broad range of temperatures showed to be a powerful tool to detect electrostrictive and magnetostrictive effects. Anomalies in the temperature dependence of the dielectric parameters (f(R) (characteristic frequency) and the dielectric strength Delta epsilon (characteristic of the dispersion)) have been observed at T-N and T-C for all samples, indicating that the coupling between the ferroelectric and antiferromagnetic orders occurs "via strain" and confirming the high sensitivity of microwave dielectric measurements to probe weak transitions in bulk ceramics. (AU)

• FAPESP's process: 08/04025-0 - Nanostructured multifunctional multiferroic materials: synthesis, properties, phenomenology and applications
• Grantee: José Antonio Eiras
• Support Opportunities: Research Projects - Thematic Grants
• FAPESP's process: 10/11187-6 - Determination of the magnetoelectric coupling coefficient in single phase multiferroic materials
• Grantee: Barbara Maraston Fraygola
• Support Opportunities: Scholarships in Brazil - Post-Doctoral