Li-Mn ferrites for high-speed computer memory applications

The high Curie temperature region of the ternary system Li
0.5
Fe
2.5
O
4
-MnFe
2
O
4
- Mn
3
O
4
has been investigated. Toroidal cores were fired using the two-step firing technique, and nearly all compositions investigated produced square
S
curves with thresholds between 4 and 10 Oe. When optimized for thresholds between 4 and 6 Oe, a compositional region was found, which combined good squareness and fast switching with low temperature and stress sensitivities. Substitutions of up to 0.1 atom of Zn for Mn in these compositions increased voltage outputs uV
1
and rV
1
without significantly affecting the other useful properties.