On the specific heat of compounds with spinel structure - II. Zinc ferrite, a paramagnetic compound with magnetic ion occupying the octahedral site

The representation of the lattice vibrational component of the specific heat for compounds with cubic spinel structure used in part I is applied to the paramagnetic substance ZnFe2O4 Analysis of the experimental data over the temperature range 10–350 K reveals a magnetic contribution in the neighbourhood of the Néel point in reasonable agreement with the theoretical calculations of Tachiki & Yosida (1957) and an anomaly at 75 K which is attributed to transitions by the Fe3+ ion between the two equivalent potential minima within the octahedral site. Further analysis of the tail of this anomaly, which varies inversely as the square of the temperature for almost 90 K, leads to an estimated height for the potential barrier of 14.8 ± 0.5 x 10-3 eV.