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Three gadolinium(III) tungstates (II-Gd2WO6, CoGd4W3O16, and
ZnGd4W3O16) have been prepared by the solid-state reaction method using
stoichiometric mixtures of the WO3, Gd2O3, CoWO4 or ZnWO4. The EPR measurements
have been done at room temperature for all three samples. A very intense
asymmetric EPR line of gadolinium(III) ions has been recorded. The intensity and
the linewidth essentially depended on the metal (M(II)=Co(II) and Zn(II)) ions in
the crystalline matrix. The difference of the linewidth and intensities is
arising from magnetic interactions between magnetic ions, especially for the
system with coexisting two different magnetic ions. It was estimated that the
exchange field in the II-Gd2WO6 and α -Fe2WO6 systems is similar but differs
significantly in its polymorphic modification. For new divalent metal and
gadolinium(III) tungstates (CoGd4W3O16 and ZnGd4W3O16) the exchange field is
modified by about 6% after substitution of metal(II) magnetic ions for a non
magnetic ion.
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