VALENCE STATE CHANGE OF Fe IMPURITIES IN LiNbO3 AFTER X-RAY IRRADIATION J. Lauer, H. D. Pfannes et W. KeuneJ. Phys. Colloques, 40 C2 (1979) C2-561-C2-563DOI: https://doi.org/10.1051/jphyscol:19792195
