Elastic scattering of electrons by gadolinium and barium atoms

Total and differential cross-sections for elastic scattering of electrons f rom gadolinium and barium atoms in a wide energy range were calculated. In the low- and intermediate-energy regions, the phase theory of elastic scatt ering was used. At low incident energies (<10 eV), an additional polarizati on potential was introduced. At high incident energies, the Born approximat ion (keV range) and the Rutherford formula (MeV range) were applied. Our re sults are in rather good agreement with experimental data of Romanyuk et al , (Pis'ma Zh. Eksp. Teor. Fit. 32 (1980) 472) for elastic scattering of ver y-low-energy electrons from barium atoms which confirm its reliability. Thi s agreement is important because these experimental results are in serious disagreement with theoretical calculations of Szmytkowski and Sienkiewicz ( Phys. Rev. A 50 (1994) 4007). (C) 2000 Elsevier Science B.V. All rights res erved.