EPR and Magnetic Susceptibility Studies of Calcium-Borate Oxide Glasses Containing Iron Ions.

EPR and magnetic susceptibility measurements have been performed on xFe[sub 2]O[sub 3] · (100 - x)[3B[sub 2]O[sub 3] · CaO] glasses with 0 < x ≤ 40 mol%. The Fe[sup 3+] ions in sites of distorted octahedral symmetry and clustered formations containing both Fe[sup 3+] and Fe[sup 2+] ionic species were found. Dipolar and magnetic super-exchange interactions involving iron ions were revealed to depend on the iron content of the sample. [ABSTRACT FROM AUTHOR]