The standard enthalpies of formation of uranium compounds. XV. Strontium uranates

U(v) in metal uranates: a combined experimental and theoretical study of MgUO4, CrUO4, and FeUO4

“…In addition, the present DFT and calorimetry results for the formation energies of for MgUO 4 , FeUO 4 and CrUO 4 are compared with previously published experimental results, 2,[13][14][15]18 for MUO 4 with M = Ca 2+ , Sr 2+ and Ba 2+ . CaUO 4 has a rhombohedral structure with space group R3 ˉm; the lattice parameters are a = 6.25 Å and α = 36.0°.…”

“…Thus these U(V) containing monouranates, with their simple stoichiometries, allow in-depth structural and stability investigations. In spite of the increasing attention to these compounds, only some of their structural characteristics have been studied, 2,[8][9][10][11][12][13][14][15][16][17][18][19][20][21] and among those studies, few have used spectroscopic methods to probe local structures. 11,12,17,19,20 The oxidation state of U in MgUO 4 is generally regarded to be hexavalent, 11,21 yet those of U in CrUO 4 and FeUO 4 are less certain.…”

“…11,12,17,19,20 The oxidation state of U in MgUO 4 is generally regarded to be hexavalent, 11,21 yet those of U in CrUO 4 and FeUO 4 are less certain. 8,9 Moreover, there is limited thermodynamic data available for these simple monouranates, 2,10,[13][14][15][16]18 MgUO 4 was first synthesized by Haag et al 22 using solid state methods. It has an orthorhombic structure with the space group Imam; the lattice parameters are a = 6.52 Å, b = 6.59 Å, and c = 6.92 Å.…”

Thermal conductivity of strontium uranates

“…Six uranates, viz, Sr 3 UO 6 , Sr 2 UO 5 , Sr 3 U 2 O 9 , SrUO 4 , Sr 2 U 3 O 11 and SrU 4 O 12:8 are known to exist in the strontium-uraniumoxygen system [1][2][3]. These uranates have been studied extensively with respect to their preparation, characterization, crystallographic, thermodynamic, thermal expansion and electrical transport properties [1][2][3][4][5][6][7][8][9][10]. However, attention has not been given so far to their thermal transport properties.…”