Solid-state synthesis and characterization of new cadmium and rare-earth metal molybdato-tungstates Cd0.25RE0.50(MoO4)0.25(WO4)0.75 (RE = Pr, Nd, Sm–Dy)

New cadmium and rare-earth double molybdato-tungstates Cd0.25RE0.50(MoO4)0.25(WO4)0.75 (RE = Pr, Nd, Sm–Dy) were prepared by the solid-state reaction technique from CdMoO4 and adequate RE2(WO4)3. The obtained compounds crystallized in the scheelite-type structure and showed solubility in CdMoO4 forming CdxGd2 − 2x(MoO4)x(WO4)3 − 3x solid solutions for 0.50 < x < 1.00. All the obtained phases were characterized by XRD, DTA-TG, IR and EPR methods. The EPR measurements of gadolinium containing samples confirmed that Gd3+ ions were located at octahedral positions. With the increasing gadolinium content the exchange and dipole–dipole interactions led to a totally antiferromagnetic type of interaction in the Gd3+ chains network.