Observation of Moessbauer spectrum without utilizing Doppler motion

New Moessbauer methodology without utilizing Doppler modulation is reported. A paramagnetic PdFe source held at liquid He temperature is used for the energy modulation of γ-rays which is achieved by the Zeeman effect on Fe nuclei in the source. 'Zeeman-mode' Moessbauer spectra are measured on an Fe metal foil and a single crystalline FeTiO3 specimen. The latter experiment, making the most of the circularly polarized γ-rays from the magnetized source, suggests that this new method is effective in separating the absorption lines into individual sublattice contributions in antiferro- or ferri-magnetic materials. It is further proposed that a magnetized paramagnetic Moessbauer source is useful in measuring a polarimetric Doppler-mode Moessbauer spectrum. (Auth.)