Lattice Enthalpies of Lanthanide Orthovanadates LnVO4

Abstract

Abstract. Lattice enthalpies Δ L H° of lanthanide orthovanadates, LnVO 4 (Ln = Ce -Lu, except Pm) have been determined from the Born-Haber thermochemical cycle and compared with those calculated by an empirical equation. Two different sets of enthalpies of formation of LnVO 4 , from oxides (Ln 2 O 3 , V 2 O 5 ) and from elements, have been used but the differences in Δ L H° are small. The Born-Haber cycle in both routes yields close values of Δ L H° to those obtained after an empirical equation proposed by Glasser and Jenkins. It has been found that the partial derivative of the lattice enthalpies to the molar volumes corresponds by magnitude and dimension to the shear moduli of these crystals. (doi: 10.5562/cca2298)

Equation of state and electronic properties of EuVO4: A high-pressure experimental and computational study

“…The knowledge on mechanical properties of the zircon phase has been completed by determining the value of shear modulus [18]. IN a recent DFT study [19] performed in the 0 -15 GPa pressure range the equation of state of the EuVO 4 -zircon phase has been determined, with bulk-modulus values of 121 and 126 GPa obtained by fitting an EOS to theoretical data and from the calculation of the elastic constants, respectively.…”

Lattice enthalpies of lanthanide orthoferrites LnFeO3

“…Similar relationships have been observed in our previous studies on lanthanide complex oxides. [19][20][21][22]…”

“…The amount of molar energy binding the ions in the crystalline LnFeO 3 is a basic quantity for this series of compounds. In this paper we follow our research interest in the lattice enthalpies of various groups of lanthanide compounds, namely: LnAlO 3 , 19 Ln 3 Ga 5 O 12 , 20 Ln-VO 4 , 21 and LnPO 4 . 22 The purpose of this work is to determine the lattice energies of LnFeO 3 by the Born-Haber cycle and to relate the results to certain mechanical properties.…”