Impact of copper substitution on the structural, ferroelectric and magnetic properties of tungsten bronze ceramics

The copper substituted tungsten bronze ceramics with generic formula Ba₅CaCu_XTi_2-xNb₈O₃₀(x = 0.0, 0.02, 0.04, 0.06 and 0.08) were successfully synthesized for the first time by solid state reaction method. X-ray diffraction (XRD), Scanning electron microscopy (SEM) and energy dispersive X-ray analysis (EDAX) were utilized to examine the different structural parameters and elemental compositions. XRD study depicted the single phase tetragonal structure having space group P4bm. The crystallite size was observed to be in the range 14.4-30.23 nm. The coexistent of ferroelectricity and magnetism was established by P-E and M-H measurements. The P-E loop study indicated an increase in the coercive field (11.805-23.736 kVcm^-1) while the M-H study depicted adecrease in the magnetization (7.65 × 10^-4-5.32 × 10^-4 emu/g) with the incorporation of Cu²⁺ ions. Raman spectrum depicted that there is shift in the position of Raman modes with the substitution of copper which revealed one-mode behavior in the synthesized ceramics.