Anisotropy and Relaxation Effects of Co2+ Ions in LiTi Ferrite.

Abstract

Abstract : Microwave power absorption and hysteresis loops were studied on a series of ferrite materials prepared from a standard LiTi spinel host with Co(2+) additions in amounts up to 0.05 ions per formula unit. Experimental results over this concentration range indicate that the rapid relaxation of Co(2+) causes X-band pek power thresholds to increase by a factor of more than 100 and magnetic loss parameters by a factor greater than ten. The usual strong effects of Co(2+) positive magnetic anisotropy, however, were not found in either ferrimagnetic resonance linewidths or hysteresis loop parameters. As a consequence, it is concluded that peak power thresholds can be raised substantially by Co(2+) additions with a modest penalty in magnetic loss, but without the catastrophic deterioration of the hysteresis loop observed previously in undiluted lithium ferrite.