ZnFe2O4 Phases Research Articles

Synthesis and characterization of ZnFe2O4/ Mn2O3 nanocomposites

In this work, spinel zinc ferrite (ZnFe2O4), manganese oxide (Mn2O3) nanoparticles (NPs) as well as a series of ZnFe2O4/Mn2O3 nanocomposites (NCs) with varying Mn2O3 ratio from 10 to 50 wt. % were synthesized by co-precipitation route. The structural, optical, electrical, and magnetic properties of ZnFe2O4/Mn2O3 NCs were examined by X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy, transmission electron microscopy (TEM), ultraviolet–visible (UV–Vis) spectroscopy, photoluminescence (PL) emission, DC electrical conductivity, and vibrating sample magnetometer (VSM). The XRD analysis demonstrated the existence of Mn2O3 and ZnFe2O4 phases, in addition to the formation of spinel ZnMn2O4 and α-Fe2O3 as secondary phases. The chemical interactions between the Mn2O3 and ZnFe2O4 have been confirmed by the shift in the position of the metal–oxygen (M–O) stretching modes in the FTIR spectra. The TEM images revealed the presence of cubic and spherically shaped nanoparticles in the ZnFe2O4/Mn2O3 NCs with an average size in the range of 15.52 to 19.22 nm. The nanocomposites showed strong absorption in the UV region with a calculated bandgap ranging between 3.22 and 3.26 eV. However, the nanocomposite with 10 wt. % Mn2O3 exhibited the highest photocatalytic activity under UV-irradiation as confirmed by PL spectroscopy. Moreover, the nanocomposite structure exhibited a significantly enhanced DC conductivity compared to ZnFe2O4 and attained a maximum value at 10 wt. % Mn2O3. The room temperature M-H curves of ZnFe2O4/Mn2O3 NCs displayed weak ferromagnetic behavior. The magnetization increases with increasing Mn2O3 content up to 10 wt. % and then decreases with further increase in the wt.%.

Characterization and leaching of mechanically activated zinc residue

Zinc extraction from zinc-containing residual (ZCR) was examined with the leach of sulfuric acid of original materials and the materials milled in two different mill systems. For this purpose, vibrating ball mill (VBM) and ring mill (RM) were used. In chemical analysis of ZCR, it was determined that it contains a significant amount of zinc, lead, iron and silver and consisted of mostly CaSO4.2H2O, PbO, SiO2, Fe2O3, ZnFe2O4, Al2FeO4 and PbSO4 mineral phases. It was determined in XRD analysis of samples milled at both mills that peak intensity dramatically decreased when compared to original sample.According to comparative characterization analyses of the milled samples, it was determined that through the increasing grinding time, the particles became agglomerated and an increase in grain size occurred. This situation was also supported by N2-BET and SEM analyses.While zinc extraction value of the sample milled for 1 min, which was obtained at 0.5 M H2SO4 at leach temperature of 25 °C, at the solid–liquid rate of 100:1 and during the leach time of 30 min, was 90% and 60% for, respectively, VBM and RM, zinc of 54% was determined to be extracted in the leach of the original sample, under the same conditions.

Structure and magnetic properties of Ba1−xDyxFe12−yZnyO19 synthesized by Sol–Gel auto-combustion technique

Ba1-xDyxFe12-yZnyO19 (x ​= ​0–0.1 and y ​= ​0–1) hexaferrites were produced by the sol-gel auto-combustion technique.In the XRD analyses of all samples, BaFe12O19 phase was observed as the pure state. ZnFe2O4 begins to form at x ​= ​0.02 and y ​= ​0.2 and peak intensities increases with the substution of Dy3+ and Zn2+ cations for the samples sintered at 900 ​°C and 1100 ​°C. As the temperature increases to 1300 ​°C, peaks belonging to BaFe12O19 phase were disappeared and transformed into Ba3Fe26O41 and BaZn1.2Fe16.8O27 phases at x ​= ​0.06 and y ​= ​0.6.Crystallite size decreased with increasing Dy3+ and Zn2+ substitutions for the samples sintered at 900 ​°C and 1100 ​°C. The smallest crystallite size obtained at 900 ​°C, x ​= ​0.06 and y ​= ​0.6.As the amount of substitution elements increase, saturation magnetization (Ms) and remenance magnetization (Mr) values decreased due to the formation of paramagnetic spinel ZnFe2O4 phase for the samples sintered at 900 ​°C and 1100 ​°C.The highest Mr value of 36.1 emu/g was obtained for the pure samples sintered at 1300 ​°C. It decreased sharply to 18.9 emu/g (about 50%) with the substitution of Dy3+ and Zn2+ cations at x ​= ​0.02 and y ​= ​0.2.Dy3+ and Zn2+ substituted hexaferrites sintered at 900 ​°C (x ​= ​0.06 and y ​= ​0.6) exhibited the highest Hc value of 4.84 ​kOe.

Removal of Ferrimagnetic ZnFe2O4 Impurity Phase by Li Co-Doping in Fe Doped ZnO

A simple approach is presented to remove the impurity phase of ZnFe2O4 from Fe doped ZnO. Gradual incorporation of non-magnetic Li ions reduced 5.6% phase contamination of ZnFe2O4 to negligible limit (<0.01%) from 4 at% (atomic %) Fe doped ZnO. X-ray absorption near edge spectroscopy (XANES) revealed that the most of the Fe ions were in Fe3+ state. The optical absorption spectra of Fe doped ZnO samples exhibited d-d transition between Fe ions. It also indicated the signature of ZnFe2O4 phase, which reduced gradually on Li increment. ZnFe2O4 contained samples exhibited strong magnetic ordering with spin-glass character at low temperature and weak ferromagnetism (FM) at the room temperature with disordered inverse spinel structure. However, 6 at% Li incorporated sample did not show any significant FM in the entire temperature range of 2–300 K. ZnFe2O4 is supposed to be the possible source of the observed strong magnetic ordering i.e., FM has extrinsic origin. The gradual removal of impurity phase ZnFe2O4 by increasing Li doping without damaging any intrinsic property of Fe doped ZnO is primarily due to gradual increase of tetrahedral coordination of Fe ions.

Magnetic and optical properties of synthesized ZnO–ZnFe2O4 nanocomposites via calcined Zn–Fe layered double hydroxide

Abstract In this article, Zn–Fe layered double hydroxide (Zn–Fe–CO3–LDH) precursors with 1, 2, 3, and 4 values of Zn2+/Fe3+ molar ratio were prepared by coprecipitation method at pH = 8. ZnO/ZnFe2O4 nanocomposite was obtained as the calcination process of LDH precursors. Herein, we explore a prospective strategy to synthesize the zinc ferrite nanostructure by the calcination of Zn–Fe–CO3–LDH precursors. Powder X-ray diffraction (PXRD) exhibited two phases (ZnO and ZnFe2O4). Hall method has been used to calculate the grain size of ZnFe2O4 and was obtained between 19 nm and 32 nm. Magnetic measurements of the ZnFe2O4 phase after the subtraction of the paramagnetic contribution from the whole hysteresis loop of ZnO/ZnFe2O4 nanocomposite were investigated using VSM. The high coercivity values of ZnFe2O4 nanoparticles (~2600 Oe) and low values of the anisotropy constant (0.0004–0.0796) J/m3 were observed which were useful for high-density storage devices application. The values of the optical band gap of the ZnFe2O4 phase were obtained above the bulk value (2.18–2.33 eV) due to the nanosized ZnFe2O4 nature. The Urbach tail energy of ZnFe2O4 nanoparticles was found between 160.3 and 194.1 meV which indicated high localized defect levels in the forbidden band gap of prepared samples. The refractive index relation with photon energy showed normal dispersion behavior for samples at the range below 1.8 eV and anomalous dispersion behavior at the range above 1.8 eV. The values of normal dispersion parameters were calculated in this work for ZnFe2O4 nanostructure as new results which were candidate material in telecommunication applications. All these parameters, in general, increased with the increasing of the Zn2+/Fe3+ molar ratio.

Microwave Absorption Characteristic of ZnNd&lt;sub&gt;(x)&lt;/sub&gt;Fe&lt;sub&gt;(2-x)&lt;/sub&gt;O&lt;sub&gt;4&lt;/sub&gt; System

The ZnNd(x)Fe(2-x)O4 (x = 0.0; 0.010; 0.020 and 0,030) systems were synthesized by solid reaction method from a mixture of ZnO2, Fe2O3 and Nd2O3 powders according to their mole ratio using mechanical milling techniques. In this mixture was added ethanol of 25 ml and then milled for 5 hours, after that sintered at a temperature of 1000 °C for 5 hours. X-ray diffraction patterns showed that the Nd3+ ion substitution in ZnFe2O4 with the concentration of x = 0.0 to 0.02 did not result in changes in ZnFe2O4 phase with cubic structure (space group of Fd-3m). However, the composition of x = 0.030 formed multiphases ZnFe2O4 and NdFeO3 phases. The morphological observation using Scanning Electron Microscope (SEM) showed spherical and uniform particles. Whereas the microwave absorption capability of the sample ZnNd(x)Fe(2-x)O4 system increased with the increasing concentration of x from 91.20% up to 97.80% with the highest absorption is found at a frequency of 10.24 GHz. The dielectric loss of this study is very small around 0.005 up to 0.05. It is hoped that the compound ZnNd0.02Fe1,98O4 can be applied to microwave absorbing agents at high frequencies (X-band range) in antiradar detection systems.

Geometric and electronic modification of the active Fe3+ sites of α-Fe2O3 for highly efficient toluene combustion

In the present study, catalytically inactive or low-active Ti4+ (d0) or Zn2+ (d10) ions were doped to α-Fe2O3 to tune the geometric and electronic engineering for Fe active center. X-ray absorption near edge structure (XANES) and Powder X-ray diffraction (XRD) analyses coupled with density functional theory (DFT) calculation show that the added of Ti4+ could occupy the interstitial octahedral or tetrahedral sites, resulting in surface Fe2+ species are oxidized to octahedrally coordinated Fe3+. As a result, more oxygen vacancies are generated, which improve the catalytic performance for toluene combustion. On the other hand, Fe2+ was substituted by Zn2+ ion could result in the partial destruction of hematite crystal structure, forming an additional phase of ZnFe2O4, and meanwhile part of Zn2+ ions replace the octahedrally coordinated Fe3+ sites, and therefore significantly decreasing the toluene catalytic performance. Moreover, our studies demonstrate that the combustions of toluene over Fe-based catalysts involve both the MvK and L-H mechanisms.

Hydrothermal Assisted Synthesis of ZnFe2O4 Embedded g‐C3N4 Nanocomposite with Enhanced Charge Transfer Ability for Effective Removal of Nitrobenzene and Cr(VI)

AbstractA novel hybrid nanocomposite of g‐C3N4/ZnFe2O4 was successfully prepared by a facile hydrothermal method followed by an annealing process. The obtain hybrid catalyst was systematically characterized by XRD, TEM, HRTEM, FT‐IR, UV‐DRS and XPS analysis in order to study the structural, morphological, optical properties and chemical states. The cubic phase ZnFe2O4 crystalline structure and spherical morphology with sizes in the range of 30–35 nm were adequately anchored on the g‐C3N4 sheets. The HR‐TEM image suggests the successful embedment of ZnFe2O4 nanostructures on g‐C3N4 sheets. The photocatalytic activity of the catalyst was investigated using nitrobenzene (NB) and Cr (VI) under visible light. The improved activity of ZnFe2O4/ g‐C3N4 is due to the synergetic effect of superior visible‐light utilization and effective charge carrier separation between g‐C3N4 and ZnFe2O4 nanoparticles. Hence, this heterostructure could be used as a favorable applicant for environmental remediation application for the removal of organic pollutants and metal ions in practical application.

Green synthesis of Lawsonia inermis-mediated zinc ferrite nanoparticles for magnetic studies and anticancer activity against breast cancer (MCF-7) cell lines

Magnetic spinel zinc ferrite nanoparticles have been prepared via simple, green, cost effective and eco-friendly methods. The development of a single cubic phase of prepared zinc ferrite is affirmed by XRD with an average crystallite size of 17.12 nm. FTIR analysis confirms the modes of the cubic ZnFe2O4 phase due to the stretching and bending vibrations of Zn–O (tetrahedral site) and Fe–O (octahedral site) bonds. FESEM micrographs revealed the formation of homogeneous and agglomerated ZnFe2O4 nanoparticles. EDAX spectrum shows the elemental composition of the synthesized zinc ferrite nanoparticles. Investigation of magnetic properties viz remanent magnetization, saturation magnetization and coercivity were found to be 37.0 emu/g, 42.9 emu/g and 11.9 Oe, respectively. The magnetic properties confirmed by the vibrating sample magnetometer exhibit ferromagnetic behaviour of synthesized zinc ferrite nanoparticles. Furthermore, synthesized zinc ferrite nanoparticles showed good anticancer activity against breast cancer (MCF-7) cell lines.

Electrical conductivity improvement of Fe doped ZnO nanopowders

The chemical co-precipitation process was used for the synthesis of Fe-doped ZnO nanopowders (ZnO:Fe) with varying doping concentrations from 0% to 10 %. Doping with iron caused significant alterations in the physical properties of ZnO nanopowders. The XRD analysis revealed that Fe introduction forms a secondary phase of spinel ZnFe2O4 for doping concentration higher than 1%. The average crystallite size was proven to decrease with the increase in Fe concentration. SEM images showed the formation of spherical nanoparticles, where the average grain size decreased with doping. The Fe incorporation into the ZnO host lattice was also confirmed by FTIR and Raman spectroscopy. The optical properties were strongly influenced by Fe doping. The dielectric parameters were subsequently investigated as a function of frequency and composition. The observed dielectric dispersion was interpreted on the basis of Maxwell-Wagner interfacial model and Koops phenomenological theory. Overall, Fe doping improved the electrical conductivity of ZnO nanopowders.

Mechanistic insights into the sol-gel synthesis of complex (quaternary) Co–Mn–Zn-spinel ferrites: An annealing dependent study

Synthesis conditions, cation distribution at tetrahedral and octahedral sites and their stability play very important roles in controlling phase-purity and physicochemical properties of spinel ferrite compounds. In this work, an attempt is made to understand how the progress of phase-formation and the structural and magnetic properties are influenced by the annealing temperature and nature of cations used in the synthesis of quaternary spinel ferrite ceramics. A series of Co0.8-xMn0.2ZnxFe2O4 (x = 0, 0.2, 0.4, 0.6 and 0.8) (CMZF) spinel ferrite samples were synthesized by citric acid assisted sol-gel technique followed by annealing at 400, 600 and 800 °C. To compare the progress of phase formation/stability of the cations, simple (binary) spinel ferrite reference samples, such as CoFe2O4, MnFe2O4 and ZnFe2O4, were also synthesized by the same technique and are calcined at the same conditions. In case of CoFe2O4, all the samples have single phase spinel structure, but a transformation from an inverse spinel-type to nearly normal spinel ferrite-type cation distribution is observed with increasing annealing temperature. The as-prepared MnFe2O4 sample and that annealed at 400 °C show formation of single phase spinel ferrite, while those annealed at 600 and 800 °C decomposes completely into Mn2O3, α-Fe2O3 and amorphous-FeO phases. In contrast, for ZnFe2O4 samples, a transformation from the ZnO and α-Fe2O3 phases (present in the as-prepared and up to 600 °C annealed samples) to pure ZnFe2O4–phase occurs only at/above 800 °C. Interestingly, our results show that the progress of the phase formation behavior of the CMZF samples can be predominantly considered as a combination of the behavior and energetics typically exhibited by the individual (simple) ferrite systems. Overall, our work provides the necessary impetus for achieving the phase purity and required physicochemical properties of complex ferrite systems by choosing the cations suitably, based on their nature and annealing behavior.

Biosynthesis of zinc ferrite (ZnFe2O4) nanoparticles using flower extract of nyctanthes arbor-tristis and their photocatalytic activity

In the present study, we adopted, a green approach for the synthesis of ZnFe2O4 nanoparticles using the aqueous flower extract of Nyctanthes arbor-tristis. This extract served as the reducing agent for the synthesis of ZnFe2O4. The obtained nanoparticles were characterized by X-ray diffraction studies which indicated the formation of single phase ZnFe2O4. The size of the nanoparticles was in the range of 4.5–12 nm with calcination temperature as revealed from X-ray diffraction and Transmission electron microscopy, UV-Visible spectroscopy. Photocatalysis studies were made on RhodamineB dye, to assess the degradation capability of the nanopowders calcined at different temperature.

Single-Domain Ferromagnetic Zinc-Copper Ferrite Composites for Magnetic Data Storage

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In situ formation, structural, mechanical and in vitro analysis of ZrO2/ZnFe2O4 composite with assorted composition ratios.

The investigation underline the in situ formation of ZrO2/ZnFe2O4 composites and the resultant structural, morphological, mechanical and magnetic properties. The characterization results ensured the crystallization of tetragonal ZrO2 (t-ZrO2) and ZnFe2O4 phases at 900°C. Depending on Zn2+/Fe3+ content, the composite system revealed a gradual increment in the phase yield of ZnFe2O4. The significance of monoclinic ZrO2 (m-ZrO2) is also evident in all the systems at 900°C; however, the incremental heat treatment to 1300°C indicated its corresponding loss, thus indicating the reverse m-→t-ZrO2 transition. The crystallization of ZnFe2O4 as a secondary phase in the t-ZrO2 matrix is also affirmed from the morphological analysis. Mechanical studies accomplished good uniformity in all the investigated compositions despite the variation in the phase content of ZnFe2O4 in composite system. All the t-ZrO2/ZnFe2O4 composites ensured strong ferrimagnetic features and moreover better biocompatibility and non-toxicity characteristics were displayed from in vitro tests.

ZnFe2O4/CuO core–shell structured nanoparticles: synthesis, structural and magnetic properties

Synthesis of core/shell structured ZnFe2O4/CuO nanoparticles with varying core diameter and different weight percentage of CuO phase [(1−x) ZnFe2O4/x CuO: x = 0.15, 0.30, 0.45 and 0.60] using double stage standard chemical co-precipitation method has been reported in this article. For first four samples only the diameter of core was varied and for other four samples only the weight percentage of CuO phase was varied. The existence of both cubic spinel ZnFe2O4 phase along with monoclinic CuO phase was verified by X-ray patterns recorded at room temperature. The average core diameter was in between 8 and 13 nm as estimated using Scherrer’s formula and further verified by HRTEM images. A reduction in lattice parameter with increasing core thickness and also with increasing CuO phase was observed. A notable enhancement in coercivity and saturation magnetization were observed in field cooled (5 T) hysteresis loops obtained at 5 K for the first four varying core diameter core–shell structured nanoparticles in comparison to bare zinc ferrite nanoparticles of almost same size. A decreasing trend in coercivity and saturation magnetization was also noticed in low temperature hysteresis loops for higher CuO content samples. A considerable improvement in blocking temperature (TB) as well as Neel temperature (TN) for all the different core diameter samples were also found in M(T) protocols. Both blocking temperature and Neel temperature decreased for increasing CuO content in composite nanoparticles. The room temperature M(H) plots exhibited superparamagnetic nature with insignificant coercivity and negligible remanence.

Comparative Structural Properties of Nanosized ZnO/Fe3O4 Composites Prepared by Sonochemical and Sol-Gel Methods

In this research, the synthesis of ZnO/Fe3O4 nanocomposites was conducted using sonochemical and sol-gel methods as well as natural materials as the primary raw material. The results of X-ray diffraction data analysis showed that the synthesis of nanocomposite used sonochemistry method which resulted in the sample with ZnO and Fe3O4 phases without the presence of the others. Interestingly, the sol-gel method resulted in a sample with ZnFe2O4 and α-Fe2O3 phases without the presence of ZnO. This case happened since Zn formed oxide compound in the form of spinel zinc ferrite. By using the Scherrer equation, the crystallite sizes were of about 7.5 nm for Fe3O4, 25.5 nm for ZnO, 13.6 nm for α-Fe2O3, and 11.6 nm for ZnFe2O4. The elemental compositions of the sample as the synthesis using sonochemical method were 33.08% for Fe and 66.91% for Zn. Meanwhile, the elemental compositions of the sample as the result of synthesis using the sol-gel method were 58.25% or Fe and 41.75% for Zn. Moreover, the infra-red spectrum showed that the functional group of the Fe3O4 phase was observed on the wavenumber of 550 cm−1 and 676 cm−1; the functional group of ZnO phase was found on the wavenumber of 433 cm−1; the functional group of α-Fe2O3 was detected on the wavenumber of 479 cm−1 and 551 cm−1; and the functional group of ZnFe2O4 was recorded on the wavenumber of 526 cm−1. Thereby, the sonochemical method in this study provides a new alternative in the synthesis of ZnO/Fe3O4 nanocomposite using natural material as the primary raw material.

Studies on structural and optical properties of nano ZnFe2O4 and ZnFe2O4-TiO2 composite synthesized by co-precipitation route

Zinc ferrite (ZnFe2O4) nanoparticles and ZnFe2O4-TiO2 nanocomposite have been synthesized by simple and effective co-precipitation method followed by annealing at 500 °C for 5 h. The x-ray diffraction patterns suggest ZnFe2O4 and/or TiO2 phases with no other impurities. TEM images demonstrate that ZnFe2O4 nanoparticles are spherical in shape (9 ± 2 nm) and ZnFe2O4-TiO2 nanocomposite exhibits spherical-like morphology (11 ± 3 nm). HRTEM and SAED studies further confirm the phase purity of the samples and reveal the formation of core-shell in case of the composite. The direct band gap of ZnFe2O4 nanoparticles (2.11 eV) and ZnFe2O4-TiO2 nanocomposite (2.30 eV) demonstrate their ability as visible light photocatalysts. The larger band gap of the composite may be due to the mixing effect of bandgap and the interfacial coupling effect between ZnFe2O4 and TiO2. The PL spectra with λex = 317 nm display peaks corresponding to the recombination of charge carriers in deep traps of surface localized states and lattice defects. The nature of PLE peaks for the ZnFe2O4-TiO2 nanocomposite suggest its improved photocatalytic activity compared with ZnFe2O4 nanoparticles. Such results provide new prospects for optimizing and improving the properties and performance of semiconductor nanocomposites in photocatalytic degradation of dyes and water splitting.

ZnFe2O4@g-C3N4 nanocomposites: An efficient catalyst for Fenton-like photodegradation of environmentally pollutant Rhodamine B

ZnFe2O4@g-C3N4 nanocomposites were successfully synthesized by following a template free chemical co-precipitation method and morphology observation clearly confirms the intimate contact between ZnFe2O4 and g-C3N4 phases. The photocatalytic activities were evaluated in terms of photo-Fenton discoloration towards Rhodamine B in presence of H2O2 under visible light irradiation. The as-prepared 10% ZnFe2O4@g-C3N4 nanocomposites showed remarkable photocatalytic activity with highest degradation rate of 0.09 min−1, which is almost 9 times higher than that of pure ZnFe2O4. Interestingly, ZnFe2O4@g-C3N4 nanocomposites exhibited a good recyclability without losing apparent photocatalytic activity after fifth successive runs, thus becoming a promising candidate for treatment of non-biodegradable organic pollutants in water.

Investigation of Fe-doped room temperature dilute magnetic ZnO semiconductors

Different ceramics sample of Zn1−xFexO (ZFO) series have been sintered by solid state reaction method. Single phase polycrystalline Fe-doped ZnO sample with hexagonal wurtzite structure has been obtained with x<0.03 mol. Segregation of Fe and/or its oxides have not been found in the XRD patterns. A weak secondary phase of ZnFe2O4 has been detected with x⩾0.03 mol. Presence of Ohmic conductivity has been detected in the dielectric property analysis and the reasons for this Maxwell-Wagner-Sillars (MWS) relaxation has been explained by the grain boundary barrier defect (GBBD) process. The obtained shift of diamagnetic behavior of pure ZnO samples to para-magnetic for ZFO samples has been established with the defect and impurity structure. The band gap energy for ZFO samples has been calculated between 2.85eV to 3.15eV. The results indicate the potential use of Fe doped ZnO ceramics in high frequency device applications.

(Fe, Nd) codoped ZnO micro– and nanostructures with multifunctional characteristics like photocatalytic activity, optical and ferromagnetic properties

Zn1-x-yFexNdyO, x = 0.02 and y = 0.00–0.05 were successfully synthesized via a hydrothermal method at 200 °C. XRD and Mössbauer spectroscopy indicated that (Fe, Nd) codoped ZnO, calcined at 700 °C, 3 h in air, contains hexagonal ZnO phase as main phase and traces of ZnFe2O4; no phase containing neodymium was observed. In this study, a strong powder morphology dependence on Nd concentration and calcination temperature was evidenced by SEM. The photocatalytic properties were found to depend on the sample morphology and Nd content. Thermoluminescence signal is weak compared to the undoped ZnO and the curves shape was almost independent on the doping level and dependent on the calcination temperature and was related to the structural defects induced by the synthesis and calcination. Photoluminescence spectra showed that the green-yellow band due to the oxygen related defects, decreases by Fe and Nd-codoping. Thermo-magnetization curves measured in low applied fields and the magnetic hysteresis loops recorded in the temperature range 5–380 K, indicate two superimposed magnetic regimes, one predominant above 100 K the other below 100 K. The observed magnetic order is not directly related to the dopant Fe or Nd ions, but to different type of defects.