Table 1.

Summary of metal tungstates phase formation and calculated crystallite sizes

System	X-ray phase	Crystal structure	2Θ	hkl	t (nm)
NiWO4	Wolframite	Monoclinic	23.89	100	19.3
			24.85	110	19.3
			30.87	011	17.2
BaWO4	Scheelite	Body cubic tetragonal	26.38	112	18.9
			27.99	004	17.4
Bi2WO6	Orthorhombic	Orthorhombic	28.29	131	15.5
			32.83	002	14.9