New Gd3+- and Mn2+-co-doped calcium molybdato-tungstates with the chemical formula of Ca1−3x−yMny▯xGd2x(MoO4)1−3x(WO4)3x (labeled later as CaMnGdMoWO), where ▯ denotes vacant sites in the crystal lattice, 0 < x ≤ 0.2500 and y = 0.0200 as well as 0 < y ≤ 0.0667 and x = 0.1667 were successfully synthesized by high-temperature solid-state reaction method and combustion route. Obtained ceramic materials crystallize in scheelite-type structure with space group I41/a. Morphological features and grain sizes of powders under study were investigated by SEM technique. Spectroscopic studies within the UV-vis spectral range were carried out to estimate the direct band gap (Eg) and Urbach energy (EU) of obtained powders. EPR studies confirmed the existence of two types of magnetic objects, i.e., Mn2+ and Gd3+ ions, and significant antiferromagnetic (AFM) interactions among them.
Download full-text PDF |
Source |
---|---|
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC9779354 | PMC |
http://dx.doi.org/10.3390/ijms232415740 | DOI Listing |
Materials (Basel)
October 2024
Faculty of Mechanical Engineering and Mechatronics, West Pomeranian University of Technology in Szczecin, Al. Piastów 19, 70-310 Szczecin, Poland.
New Nd-doped cadmium molybdato-tungstates with the chemical formula of Cd▯Nd(MoO)(WO) (where = 0.0283, 0.0455, 0.
View Article and Find Full Text PDFJ Phys Condens Matter
September 2024
School of Physics, University of Hyderabad, Prof. C. R. Rao Road, Gachibowli, Hyderabad 500046, Telangana, India.
The present work provides insight into the structural, vibrational, and elastic properties of scheelite-type alkali-metal perrhenates AReO(= Na, K, Rb, and Cs) via first-principles calculations. Sodium, potassium, and rubidium perrhenates are isostructural and crystallize in a tetragonal structure, whereas cesium perrhenate crystallizes in an orthorhombic structure. All the phonon frequencies and their corresponding mode assignments were estimated through the linear response method within density-functional-perturbation theory.
View Article and Find Full Text PDFInorg Chem
August 2024
School of Chemistry, The University of Sydney, Sydney, NSW 2006, Australia.
The structures and high-temperature phase transition of CaUNbO were studied in situ using synchrotron X-ray and neutron powder diffraction. Rietveld refinements provided an accurate description of the crystal structures of both the monoclinic fergusonite-type 2/ structure observed at room temperature and the tetragonal scheelite-type 4/ structure found at high temperatures. Bond valence sum analysis showed Nb to be octahedrally coordinated in the monoclinic fergusonite-type structure, akin to other NbO materials.
View Article and Find Full Text PDFMaterials (Basel)
June 2024
Institute of Solid State Physics, University of Latvia, 8 Kengaraga Street, LV-1063 Riga, Latvia.
The studies of polaronic centers in a homologous series of scheelite-type compounds WO ( = Ca, Sr, Ba) were performed using the W L-edge and Sr K-edge X-ray absorption spectroscopy combined with the reverse Monte Carlo simulations, X-ray photoelectron spectroscopy (XPS), and first-principles calculations. Protonated scheelites HWO were produced using acid electrolytes in a one-step route at ambient conditions. The underlying mechanism behind this phenomenon can be ascribed to the intercalation of H into the crystal structure of tungstate, effectively resulting in the reduction of W to W, i.
View Article and Find Full Text PDFActa Crystallogr E Crystallogr Commun
May 2024
Gymnasium in der Glemsaue, Gröninger Str. 29, 71254 Ditzingen, Germany.
Coarse colorless single crystals of lithium lutetium bis-[orthomolybdate(VI)], LiLu[MoO], were obtained as a by-product from a reaction aimed at lithium derivatives of lutetium molybdate. The title compound crystallizes in the scheelite structure type (tetra-gonal, space group 4/) with two formula units per unit cell. The Wyckoff position 4 (site symmetry ) comprises a mixed occupancy of Li and Lu cations in a 1:1 ratio.
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!