A MÖSSBAUER EFFECT STUDY OF THE QUADRUPOLE INTERACTION IN PARAMAGNETIC CHLORINE AND FLURINE CONTAINING β-FeOOH D. Chambaere, A. Govaert, E. de Grave, G. Harts and G. Robbrecht J. Phys. Colloques, 40 C2 (1979) C2-350-C2-352 DOI: 10.1051/jphyscol:19792124