An investigation of iron chromium tellurates by iron-57, tellurium-125 and iodine-129 Mössbauer spectroscopy

The⁵⁷Fe Mössbauer spectra recorded at 4.2K from the trirutile-type iron chromium tellurates of composition Fe_2?xCr_xTeO₆, where x=0–2, show that the angle θ, which describes the perpendicular orientation of the magnetic moment to the basal plane of the Fe₂TeO₆ unit cell, is not changed by the incorporation of chromium until x exceeds 1.2 At this critical limit θ begins to rapidly cant to smaller values until, at compositions approaching Cr₂TeO₆, it approaches a parallel orientation to the basal plane. The¹²⁵Te and¹²⁹I Mössbauer spectra recorded from the compound FeCrTeO₆ at 77 and 4.2K are consistent with the presence of a supertransferred magnetic hyperfine field at the tellurium nucleus ofca. 76 kG.