The effect of some transition metal oxides on the physical properties of K_0.5Na_0.5Nb_0.95Ta_0.05O₃ ceramics

Abstract

Both K_0.5Na_0.5Nb_0.95Ta_0.05O₃ (KNNTO) and (K_0.5Na_0.5Nb_0.95Ta_0.05O₃)_0.99-M_0.01, M = Co₃O₄ and Mn₂O₃ (M/KNNTO) Ferromagnetic behaviour was observed for some M/KNNTO compounds. The hardness and compressive strength of all investigated samples are given. Comparisons with similar materials are discussed. Ceramics were synthesised using a solid-state reaction method. X-ray diffraction patterns of all samples revealed that the crystal structure is orthorhombic. Field-emission scanning electron microscopy was performed. Polarisation hysteresis curves indicated a disruption of ferroelectric order with the addition of M into KNNTO ceramics. The dielectric properties of the investigated ceramics have been studied as a function of frequency and temperature.

Keywords:

• Lead-free materials
• characterisation
• ferroelectricity
• magnetisation
• dielectric properties
• hardness and compressive strength

Funding

This study was financially supported from the Faculty of Industrial Education, Helwan University, and Faculty of Science, Fayoum University, Egypt.