Magnetic anisotropy and Mössbauer spectra in disordered lithium–zinc ferrites

Single crystals of Zn doped lithium ferrite have been obtained by an improved flux method. The magnetic anisotropy and Mössbauer spectra of the system (Fe1−x3+Znx2+)[Fe(3+x)/23+Li(1−x)/2+]O4 with 0⩽x⩽0.5 have been investigated. According to the single-ion model, the magnetic anisotropy constant K1 depends mainly on the contribution of Fe3+ ions on tetrahedral sites and has always negative values (K1A≈−0.038 cm−1/ion; K1B≈0.0047 cm−1/ion for x=0.11–0.5) at room temperature. With increasing zinc content, the hyperfine magnetic field H on A sites is gradually decreased. The effect is presumably due to the spin canting and to the relaxation of the octahedral Fe3+ ions. The average reduction of the hyperfine magnetic field on B sites at 300 K is 22±2 kOe per Zn2+ nearest neighbor.