Magnetic properties of quasi two-dimensional ferric stearate

Abstract

Results are given of measurements of magnetic susceptibility, electron spin resonance, and Mössbauer effect of ferric stearate. The stearates have long chain hydrocarbons separating by about 50 Å the planes of metal ions. Thus they are excellent examples of quasi two-dimensional magnetic structures. An interesting sample seems to contain some hydroxy-ferric stearate. In this sample we observed that at high temperatures (295 K≥T≥60 K) the magnetization scaled as H/T, as for superparamagnets. Below 60 K there were deviations from this scaling, shifts in electron spin resonance fields, and splittings of the Mössbauer spectrum, indicating a transition to a state of time-independent magnetic order.