Table 1 Various parameters of the studied samples

Cell parameters (Å)

a = 9.424(3)

a = 9.428(4)

a = 9.444(4)

a = 9.443(3)

c = 6.876(2)

c = 6.876(3)

c = 6.854(3)

c = 6.863(4)

Crystallinity index (%)

1.79

1.58

0.38

0.33

Crystal size (nm)

24 ± 5

23 ± 4

13 ± 3

12 ± 3

Water content (wt.%)

5.2 ± 0.2

5.4 ± 0.3

7.6 ± 0.3

7.3 ± 0.2

Se content (wt.%)

-

-

3.71 ± 0.043

3.60 ± 0.033

Mn content (wt.%)

-

0.28 ± 0.02

-

0.29 ± 0.02

(Ca + Mn)/(P + Se)^a

1.62 ± 0.03

1.59 ± 0.02

1.53 ± 0.03

1.52 ± 0.02

(Ca + Mn)/(P + Se)^b

1.65 ± 0.06

1.64 ± 0.07

1.57 ± 0.07

1.56 ± 0.07