Synthesis of Samarium OxysulfateSm2O2SO4 in the High-Temperature Oxidation Reaction and Its Structural, Thermal and Luminescent Properties

Abstract

The oxidation process of samariumoxysulfide was studied in the temperature range of 500–1000 °C. Our DTA investigation allowed for establishing the main thermodynamic (∆Hºexp = −654.6 kJ/mol) and kinetic characteristics of the process (Ea = 244 kJ/mol, A = 2 × 1010). The enthalpy value of samarium oxysulfate (ΔHºf (Sm2O2SO4(monocl)) = −2294.0 kJ/mol) formation was calculated. The calculated process enthalpy value coincides with the value determined in the experiment. It was established that samarium oxysulfate crystallizes in the monoclinic symmetry class and its crystal structure belongs to space group C2/c with unit cell parameters a = 13.7442 (2), b = 4.20178 (4) and c = 8.16711 (8)Å, β = 107.224 (1)°, V = 450.498 (9)Å3, Z = 4. The main elements of the crystalline structure are obtained and the cation coordination environment is analyzed in detail. Vibrational spectroscopy methods confirmed the structural model adequacy. The Sm2O2SO4luminescence spectra exhibit three main bands easily assignable to the transitions from 4G5/2 state to 6H5/2, 6H7/2, and 6H9/2 multiplets.

Expanding Family of Litharge-Derived Sulfate Minerals and Synthetic Compounds: Preparation and Crystal Structures of [Bi2CuO3]SO4 and [Ln2O2]SO4 (Ln = Dy and Ho)

“…Synthetic analogs of the grandreefite structure are observed also among selenates ([Pb 2 F 2 ]SeO 4 [34] and [Ln 2 O 2 ]SeO 4 , Ln = La, Pr, Nd [35]) and chromates ([La 2 O 2 ]CrO 4 [32]). The same structure was also established for [Bi 2 O 2 ]SO 4 [36] and some rare-earth oxysulfates [Ln 2 O 2 ]SO 4 (La [29], Sm [30] and Eu [31]). In the meantime, a different atomic arrangement was suggested for [Nd 2 O 2 ]SO 4 [37].…”

“…The crystal structure of [Bi 2 CuO 3 ]SO 4 (Figure 3d) is based on alternation of continuous [Bi 2 In general, the structural architecture of [Ln 2 O 2 ]SO 4 (Figure 4b) is similar to [Bi 2 CuO 3 ]SO 4 . The current pool of data indicates that structures of the [Ln 2 O 2 ]SO 4 species for Ln = La, Sm, Eu, Dy and Ho ([29][30][31] and this work) are nearly identical except Ln = Nd[37] with suggested trigonal prismatic coordination for Nd 3+ which is relatively rare. The suggested non-centrosymmetric I222 space group was not verified.…”

“…Structurally related architectures occur when the interlayer gallery hosts various molecular anions (linear triatomic [20,21], trigonal [22][23][24][25][26], or tetrahedral [27][28][29][30][31][32][33][34][35][36][37][38] (Figure 1a-h). There are three possible orientations of tetrahedral anions between the litharge slabs (Figure 1d-f) two of which are represented in nature by the mineral grandreefite [Pb 2 F 2 ]SO 4 [27] and a slag phase [Ba 2 F 2 ]S 2 O 3 [28].…”

Micro‐Raman study of cesanite (Ca2Na3 (OH)(SO4)3) in chloride segregations from Udachnaya‐East kimberlites

“…[ 32 ] The most intense line around 1,000 cm −1 is associated with symmetric stretching of [SO 4 ] 2− groups, while the spectral bands above 1,050 cm −1 are antisymmetric stretching vibrations. [ 33 ] As can be seen from Figure 12 and taking into account that cesanite structure has two crystallographically independent SO 4 tetrahedra, it is obviously that spectral contour around 1,000 cm −1 should consists of two lines. Raman spectrum in the range of 420–675 cm −1 is related to the bending vibrations of [SO 4 ] 2− .…”

Structural Features of Y2O2SO4 via DFT Calculations of Electronic and Vibrational Properties

“…As to the Re 2 O 2 SO 4 oxysulfates, the crystal structure of Nd 2 O 2 SO 4 [28] was solved in the non-centrosymmetric (I222) space group and thus this class of compounds can be a candidate for NLO materials. On the other hand, the crystal structure of Sm 2 O 2 SO 4 [29] and Eu 2 O 2 SO 4 [30] was solved in the centrosymmetric (C2/c) space group.…”