Paramagnetic Anisotropy of CdGd2(WO4)4-δ Single Crystal

CdGd2(WO4)4-† single crystal was grown using the Czochralskiʹs method. The crystal structure was tetragonal scheelite with lattice parameters a = b = 0.5203 nm and c = 1.1359 nm. There were vacancies of (WO4)2-, therefore, there were some Gd2+ ions. Langevin paramagnetism and anisotropy were observed from the σ-T curves at room temperature. The susceptibility χ// was 3.5018 × 10−3, and χ was 3.4403 × 10−2. The anisotropy was also observed in the electron spin resonance (ESR) experiments. The anisotropic Landé factors were g// = 2.1333 and g⊥ = 2.8411. The direction of easy magnetization was in the a-b plane. Anisotropic paramagnetic Curie constants C// and C⊥ were not only related to macroscopic σ that was observed through the experiment, but were also related to J⊥ and J//, which were the microscopic quantum numbers of the Gd2+ and Gd3+ ions. Based on the detailed analyses, the proportion of 36.8% of Gd3+ ions to 63.2% of Gd2+ ions in the Gd ions of the CdGd2(WO4)4-σ crystal was calculated, and δ was 0.638 in the single crystal.