Effect of Quadrupolar Polarizability upon Field Gradient in Tetragonal Lattices

Abstract

In the course of investigating sources of electric field gradient in the body-centered tetragonal structure of indium, a study of the effect of quadrupole moments induced in the ions themselves has been made. An eight-figure table covering a wide range of $\frac{c}{a}$ values and giving the axial field gradient per unit axial quadrupole moment in a tetragonal lattice of quadrupolarly polarized ions has been constructed. The effects of the ions at (\textonehalf{},\textonehalf{},\textonehalf{}) and those at (0,0,0) have been listed separately in the interest of versatility.Using a rough estimate of the quadrupolar polarizability of the indium ion, the net effect of the induced moments in this material is shown to be small. Larger effects could be expected in other substances.