Antiferromagnetism in an oxide semiconducting glass

The magnetic structure of a 55 mol% FeO–45 mol% P 2 O 5 semiconducting glass containing various relative concentrations of Fe 3+ and Fe 2+ has been studied by ESR techniques over the temperature range −190 to 300 °C. It was determined that the iron ions in the glass matrix are antiferromagnetically coupled in Fe 3+ –Fe 2+ ion pairs. The isolated Fe 3+ −Fe 2+ ion pairs. The isolated Fe 3+ ions were found to be in orthorhombic crystalline fields with λ = 1/3 and 0.23 < D < 0.8 cm −1 , where D and λ are constants in the spin Hamiltonian. Heat treatment of the glass samples caused precipitation of Fe 3+ ‐rich crystalline phases, and it was determined that the Fe 3+ ions in these phases were antiferromagnetically aligned.