Chemical bath deposition synthesis of Dy2(CO3)3, and their evolution to Dy2O3 transition

Abstract

Dy2(CO3)3 (dysprosium carbonate) nanocrystals, are successfully prepared at 60 °C, applying Chemical Bath Deposition technique. The powders are thermal annealing temperature (TAT) of 300 °C, 500 °C, 700 °C and 900 °C in air atmosphere. By XRD patterns, Dy2(CO3)3 where identified in the orthorhombic-phase. Structural evolution is observed for Dy2(CO3)3→Dy2O3 transition by correlating interplanar distance and grain size and Urbach energy tails, is applied to extract information on crystalline defects. The DSC experimental curve, shows a weight loss and a slight weight loss before ∼450 ◦C, indicating the absence of absorbed water or other polutants. The optical study in the %T, %R, Absorbance and d(D.O)/dE are investigated, the following optical responses are recorded: The non-hypersensitive 4F9/2→6H15/2 electronic intra-transitions (4fs→4fs) in Dy3+ cation being a magnetic dipole transition is insensitive to environment. Intense absorption band: 6H15/2, 6H11/2→6H9/2 is recorded at UV-region. Dy2O3(s) show absorption bands located at ∼457 nm (∼2.71 eV), assigned to Dy3+ cation of 4F9/2⟶6H15/2 electronic intra-transition. The dOD/dE vs. Energy (eV) spectra shows absorption bands situated at ∼324 nm (∼3.82 eV), ∼348 nm (∼3.56 eV), ∼363 nm (∼3.41 eV), ∼386 nm (∼3.21 eV) and ∼399 nm (∼3.10 eV) to 6H15/2→4M17/2, 6H15/2→6P7/2, 6H15/2→6P5/2, 6H15/2→4K17/2 to 4fs→4fs electronic intra-transitions of Dy3+ cation. The PL emission band located at UV-Vis region, are overlapped with the 4fs→4fs electronic intratransitions, typical of the Dy3+ cation, which are deconvoluted and associated with intrinsic crystalline defects.