BNT powder was prepared using the soft combustion technique. Bismuth nitrate
and sodium nitrate were mixed and dissolved at 40 ◦C in 2-methoxyethanol. For Prdoped
BNT synthesis, praseodymium nitrate (5, 10, or 20 mol%) was mixed with
bismuth nitrate and sodium nitrate. 1mol of glycine was added into the solution to
aid the combustion process. In parallel, 1mol of titanium isopropoxidewasdissolved
separately in 2-methoxyethanol and acetylacetone. The acetylacetone functions as
a chelating agent in the reaction. Next, the prepared titanium solution was continuously
stirred into the prepared bismuth and sodium solution or Pr-doped bismuth
sodium solution for 2 h, producing a yellowish homogeneous solution. The mixture
was then heated to 130 ◦C on a hot plate with continuous stirring. Evaporation transformed
the mixture into a viscous brownish solution. Continued heating at 130 ◦C
led to combustion and the formation of foam. Next, the foam was ground using an
agate mortar to form fine powder. The resulting powder was calcined at 800 ◦C for
3 h. The calcined powder was then pressed into pellets using 52.2 bar of pressure.
The pellets were then sintered at 1100 ◦C for 3 h at a heating rate of 5 ◦C/min