The effect of Ge⁴⁺ substitution in lithium ferrites

X‐ray diffraction, infrared, and Mössbauer spectroscopy techniques are used to investigate Li_{0.5 + 0.5x} Ge_xFe_{2.5 ‐ 1.5x}O₄; x ≦ 0.5. The polycrystalline samples show single‐phase spinel structure. The lattice constant for x ≧ 0.2 is found to be nearly constant, but smaller than for x = 0. A small component of Fe²⁺ has been detected in the IR spectra. The Mössbauer absorption patterns give magnetic sextets superimposed on a paramagnetic component that increases with increasing germanium content. The average hyperfine field at the A‐site is found to decrease faster than at the B‐site. A consistent interpretation of the information obtained from the different methods is provided. It is also suggested to give a qualitative explanation for the differential variation of the average hyperfine fields at the two sites on the basis of supertransferred hyperfine interactions.