Synthesis and magnetic properties of Cu0.5Ni0.5Fe2O4 nanoparticles produced by glycothermal and hydrothermal processes

Abstract

Cu 0.5 Ni 0.5 Fe 2 O 4 nanoparticles have been synthesized in ethylene glycol solution and in deionised water. The glycothermal reaction was carried at 200 • C under gauge pressure of 100 psi. The hydrothermal treatment was done at 100 • C under zero pressure. Complete single-phase cubic spinel structure in the samples made by glycothermal (sample G) and hydrothermal (sample H) processes formed after annealing at 600 • C and 900 • C respectively. The coercive field of sample H increases from 72 Oe to 133 Oe after sintering at 700 • C and then decrease to 11 Oe on sintering at 1000 • C. This variation is attributed to surface effects and crossover from single to multidomain behavior due to increasing particle size.

Structural and magnetic properties of MnxCo1−xFe2O4 ferrite nanoparticles

“…This indicates that the s electron density is not affected by substitution of Co by Mn atoms or by thermal relaxation of the lattice. The values of line width and hyperfine fields are also comparable to those reported for similar compounds [11]. However, in the present case we observe an enhancement of hyperfine fields at both A and B sites for the Mn 0.…”

Структурные преобразования наночастиц Ni-=SUB=-1-x-=/SUB=-Cu-=SUB=-x-=/SUB=-Fe-=SUB=-2-=/SUB=-O-=SUB=-4-=/SUB=- в зависимости от количества ионов Сu

“…Эффект Мёссбауэра широко используется для структурных исследований ФШ [41,42]. Представленные в работе [43] Критерий, используемый для определения принадлежности зеемановских секстиплетов МС к А-или В-подрешеткам, основан на величинах изомерных сдвигов и квадрупольных расщеплений [74]. Величина электронной плотности ионов Fe 3+ в A-узлах, больше, чем ионов в B-положениях, следовательно, сверхобменная связь Fe−O в A-положениях короче, чем в B-подрешетке и ковалентность меньше.…”