Evolution des parametres de maille de LiNbO_3 dope par le potassium ou le magnesium

摘要

The evolution of a and c lattice constants of nonstoichiometric LiNbOs lithium niobateis compared with litterature results. Addition of potassium oxide to the melt induces shortening of both parameters towards the stoichiometry, without incorporation in the crystal of potassium. On the contrary, with magnesium oxide addition in the melt, a lengthening of both parameters is connected with substitution of lithium by magnesium in a LiNbOs-Mg+M^Og solid solution which obeys Vegard's law.