Re-entrant spin glass and Magnetoresistance in Co0.2Zn0.8Fe1.6Ti0.4O4 spinel oxide
نویسنده
چکیده
We have investigated the static and dynamical response of magnetic clusters in Co0.2Zn0.8Fe1.6Ti0.4O4 spinel oxide, where a sequence of magnetic phase transitions, i.e, paramagnetic(PM) to ferromagnetic (FM) state at TC ≤ 270K and ferromagnetic to canted spin glass (CSG) state at Tf ≤ 125K is observed. The time dependence of remanent magnetization shows a non-equilibrium spin dynamics in the CSG state and above 130K an weak time dependent relaxation characterizes a canted ferromagnetic state which is followed up by no relaxation effect in the paramagnetic state. The field dependence of the magnetization confirms the absence of long range ferromagnetic order in the system. This brings the idea that all the spins are not necessarily be infinite ordered inside the clusters due to spin canting effects. The variation of the ferromagnetic and antiferromagnetic components and magnetic disorder inside the clusters shows some interesting magnetic and electrical properties in the system, viz, field induced transition in M vs H data, re-entrant magnetic transition in ac susceptiblity vs T data and re-entrant semi-conducting behaviour in resistivity vs T data. e-mail address:[email protected] 1
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