SINGLE-CRYSTAL MOSSBAUER-SPECTROSCOPY ON THE 3 PRINCIPAL SECTIONS OF A SYNTHETIC FAYALITE SAMPLE IN THE ANTIFERROMAGNETIC STATE

The present work reports Mossbauer investigations for several temperat ures below T-N on fayalite single crystal sections cut perpendicularly to the crystallographic a- and b-axis (Pnma). The previously detected correspondence between the c-component of the magnetic moment on M1 f rom neutron diffraction and our own Mossbauer measurements published e lsewhere are confirmed for the other principal sections to a large ext ent. Small humps in the angular dependence of two components of the in ternal magnetic field H(0) on T below T = 23 K are in good agreement w ith magnetometric and calorimetric data published elsewhere; a reinter pretation of single reflection neutron data has been possible by our r esults. Moreover, the axes of the electric field gradient (efg) are or iented within the crystallographic axes for the M1-site at low tempera tures. The violation of symmetry on the M2 position as a result of our previous investigations could be confirmed for the section perpendicu lar to a, but not with respect to b. A possible explanation in terms o f saturation effects of large Line intensities al the expense of the s mall ones is given in the context.