QUASI-ELASTIC SCATTERING IN PRAL3

Using the long-wavelength polarisation analysis neutron spectrometer ( LONGPOL) fitted with time-of-flight energy analysis, the crystal field excitation spectrum of the rare earth trialuminide PrAl3 was measured , and transitions of 4.5 and 3.7 meV were observed to take place betwe en states of the Pr3+ ion. In addition, the neutron polarisation analy sis of the elastic scattering resulted in a clearer separation into nu clear elastic and magnetic quasielastic components, the latter resulti ng from the neutrons' interaction with excited Pr3+ ions. Calculations of transition probabilities were performed, and this led to the concl usion that the quasielastic scattering and crystal field transitions h ad been successfully observed and distinguished from other scattering events in PrAl3. (C) 1998 Elsevier Science B.V. All rights reserved.