ELECTRON-TRANSFER THROUGH ORDERED METALLIC CHAINS IN LINBO3(MG, ZN)ME(3D)

In crystal and ceramic LiNbO3 double doped with Mg or Zn above the thr eshold concentration (C-Mg,C-Zn greater than or equal to 4-6 mol%) and with transition metals of the 3d group (Cr, Fe, Mn) non-resonant micr owave absorption (NRMA) dependent on the magnetic field was studied. P eak-like dependencies of the NRMA signal intensity on the concentratio n of dopants and stoichiometry of lithium niobate were found. The EPR line of mobile electrons (Delta B = 30 mT) with g = 2.0023 was detecte d. The interaction energy between the substitutional impurities of Mg and Cr was calculated. It was concluded, that in LiNbO3 : (Mg, Zn) : ( Cr, Fe, Mn) ordered metallic chains exist with electron conductivity. (C) 1998 Elsevier Science B.V. All rights reserved.