where l is the wavelength of Cu Ka radiation (0.15418 nm [1]), y
the Bragg angles of the (111) peaks of the XRD patterns, L the
average crystallite sizes of SrCO3 and BaCO3, k the constant (0.89),
and B the full widths at half maximum of the (111) peaks. They
were 10.94 nm for SrCO3 and 15.29 nm for BaCO3. The particle
size of the first was smaller than that of the second, in accordance
with the lesser ionic radius and atomic mass of the first as
compared to the greater ionic radius and atomic mass of the
second.