Effect of pressure on the resistivity of spinel ferrite

The far-infrared spectra of six mixed ferrites (CdxCo1-x+tTitFe2-2tO4; x = 0.2, 0.00 <= t <= 0.25) in the range 200-1000cm(-1) are reported. Two strong high-frequency bands v(1) and v(2) are observed. The first one v(1) is assigned to the tetrahedral and the second v(2) is assigned to the octahedral site. A small kink v(3) around near v(2) is observed and its intensity increases with divalent octahedral metal ion concentration. Seebeck coefficient measurements showed that the substitution of tetravalent ion Ti4+ does not change the polarity of the Seebeck coefficient from p- to n-type. The activation energy and the carrier mobility It were also calculated. The effect of mechanical pressure on the dc resistivity was investigated. (C) 2007 Published by Elsevier B.V.