Enthalpy of formation and lattice energy of bismuth perrhenate doped by neodymium and indium oxides

For the first time the standard formation enthalpy of Bi12.5Nd1.4In0.1ReO24.5 has been determined by solution calorimetry by combining the solution enthalpies of Bi12.5Nd1.4In0.1ReO24.5, 1.4NdCl3 + 0.1InCl30.1InCl3 mixture in 2 M HCl and literature data. The lattice energy for Bi12.5Nd1.4In0.1ReO24.5 has been calculated using Born-Haber cycle. The dependence of lattice energy for Bi12.5R1.5ReO24.5 (R - rare earth element) from radius of rare earth metal was constructed. It was established that dependence was linear and had form: Ulat = −129450 + 45070 rR. Linear character of experimentally obtained dependence was explained using modified variant of Kapustinskii formula obtained by us as following: U = A + BrR.