INFLUENCE OF AN EXTERNAL MAGNETIC FIELD ON THE RELAXATION RATE ON THE FE(II) ION IN SUBSTITUTED ACETYLACETONATO COMPLEXES C. NICOLINI, J. P. MATHIEU and J. CHAPPERT J. Phys. Colloques, 37 C6 (1976) C6-121 DOI: 10.1051/jphyscol:1976628