Isochronal annealing of irradiated single crystal hematite

Abstract

The magnetic properties of irradiated single crystal hematite are recovered by annealing. With increasing annealing temperature the amount of the weak ferromagnetic (WF) phase decreases at measurement temperature of 140 K, then the new low‐temperature transition temperature decreases while the Morin temperature increases. The annealing at 163 to 178 °C leads to the disappearance of the WF phase at low temperatures. The Morin transition temperature reaches its nonirradiated value only after annealing at 455 °C. In the single crystal hematite irradiated with 29 MeV α‐particles two stages of annealing are observed.

Microstructural and Magnetic Studies on Hydrothermally Prepared Hematite

“…Formation of such very fine hydrous iron(III) oxide has also been reported earlier erties of the system. The transition from weak ferromagnetic (WF) phase to antiferromagnetic (AF) phase has also been in the hydrolysis reaction of iron(III) chloride and iron(III) nitrate solution, investigated by gel filtration, ultracentrifu-shown to be influenced by particle size (14, 24-26), disorder induced by irradiation (27)(28)(29), and doping (30-32). sion and light-scattering techniques (21)(22)(23)).…”