ELECTRIC-FIELD DEPENDENT SWITCHING IN LI-CD FERRITES

Stoichiometric Lithium-Cadmium Polycrystalline Ferrite System (Li0.5Fe 0.5), Cd-x Fe-2 O-4, prepared by standard ceramic route exhibits CCNR- type electrical switching, when the field is applied across the mater ial in the pellet form. The importance of the result is that the prope rty is exhibited by the material which is furnace cooled and is not su bmitted to any additional thermal treatment. Further, the switching is observed at room temperature (25 degrees C) and at relatively low fie lds. The addition of Cd++ just by X=0.1 reduces the requirement of fie ld drastically, however, further addition of Cd-content reverses the t rend. The I-V characteristics are similar to those of three junction f our layer semiconductor structure and there is no aging effect. The ph enomenon is observed in all the compositions of the series irrespectiv e of ferri or paramagnetic in nature. The system provides exception to the proposed models and therefore, no fully satisfactory explanation of this property looks to be possible at this stage, however, the expe rimental results will be important as it will lead to developing elect rical switching devices.