57Fe Mossbauer study of a secondary phase in FeSe1-x with a large quadrupole splitting

We have studied the hyperfine interactions in samples belonging to the Fe-Se system. Several samples with various concentrations of selenium were synthesized and investigated. The objective was to find synthesis conditions increasing the concentration of a secondary Fe-Se phase with a rather large quadrupole splitting of similar to 1.7 mm/s. At T (m) a parts per thousand 104 K this secondary phase undergoes a magnetic ordering.