Direct Preparation of the Nanocrystalline MnZn Ferrites by Using Oxalate as Precipitant

Abstract

Oxalate was generally used as a precipitant for synthesis of MnZn ferrites during the co-precipitation process. However, the MnZn ferrite couldn't be directly obtained and a calcination process was needed. In this research, we reported a direct preparation of the MnZn ferrite nanoparticles by using co-precipitation method, together with refluxing process. XRD measurements proved that crystallite size of the obtained samples increased with an increase in pH value of the co-precipitation solution, and that the crystallite size of about 25 nm was obtained for the sample at a pH of 13. This sample showed the maximum Ms of 58.6 emu/g, which was about one times larger than that of 12 (pH value). Calcination to the obtained samples result in an enlargement in their crystal size and an improvement in their magnetic properties with an increase in temperatures. The samples calcinated in CO2 + H2 atmosphere presented good stability, and the maximum Ms value of 188.2 emu/g was obtained for the 1100˚C-heated sample. Unfortunately, precipitation of some Fe2O3 at 800˚C suggested poor stability of the nanocrystalline MnZn ferrite in N2 atmosphere.

A review on MnZn ferrites: Synthesis, characterization and applications

“…In addition, this review critically analyses methods and discusses on the choice of synthesis method for use of MnZn in a given application. In brief methods such as sol-gel method [96][97][98][99][100][101], co-precipitation method [85,[102][103][104][105][106][107][108][109], conventional ceramic technique [110,111], hydrothermal method [112][113][114], citrate precursor method [115][116][117], solid state reaction method [118], auto-combustion method [119] and microemulsion method [120] for the synthesis of MnZn are discussed. Various advantages and disadvantages of the synthesis methods are shown in Table 1.…”

“…In the class of soft ferrites, MnZn ferrites are preferred due to high permeability [122][123][124][125][126][127], saturation induction [128][129][130], low power losses [34,[131][132][133][134][135][136][137][138] and high magnetic induction [139,140]. MnZn ferrites are of great interest due to their wide range of applications such as hyperthermia applications [141], power applications [109][110][111], magnetic fluid [145], high frequency power supply, memory storage devices, TV sets, biomedicines [146], magnetic resonance, catalysis etc. There is a continuous progress in the size and shape control of MnZn ferrites and also on the morphological and magnetic properties of MnZn ferrites by using different methods [147] of synthesis like sol-gel method [96][97][98], co-precipitation method [85,[102][103][104][105][106][107][108][109]143], conventional ceramic technique [110,111], hydrothermal method …”

“…MnZn ferrites are of great interest due to their wide range of applications such as hyperthermia applications [141], power applications [109][110][111], magnetic fluid [145], high frequency power supply, memory storage devices, TV sets, biomedicines [146], magnetic resonance, catalysis etc. There is a continuous progress in the size and shape control of MnZn ferrites and also on the morphological and magnetic properties of MnZn ferrites by using different methods [147] of synthesis like sol-gel method [96][97][98], co-precipitation method [85,[102][103][104][105][106][107][108][109]143], conventional ceramic technique [110,111], hydrothermal method [112][113][114][148][149][150], citrate precursor method [115], solid state reaction method [118], autocombustion method [119,151], microemulsion method [120]. The effect of doping on the structural and magnetic properties of pure MnZn ferrites is also taken into account.…”