The magnetostriction of cobalt-manganese ferrite

Abstract

Measurements of the magnetostriction constants h1 and h2 are presented for CoxMn1-xFe2O4 in the range 2 K less-than-or-eq, slant T less-than-or-eq, slant 400 K for 0·005 less-than-or-eq, slant x less-than-or-eq, slant 1·12. The contribution of Co2+ ions to the magnetostriction constants Δh1 and Δh2 have been extracted and compared with the theoretical predictions of the single-ion model. It is found that the magnetostriction varies linearly with cobalt concentration only for x<0·20. Close agreement between the theoretical and experimental temperature dependence of Δh1 and Δh2 over the whole temperature range implies a much larger spin-orbit coupling constant (αλ similar 270 cm−1) than has hitherto been thought appropriate to this system, together with a relatively small exchange interaction (βH similar 125 cm−1).