Mn In Samples Research Articles

Debye temperature of single-crystal Cr with incommensurate and commensurate magnetic structure

Single crystals of Cr and Cr3%Mn doped with ∼0.2 at.% 119Sn were studied by means of 119Sn-site Mössbauer spectroscopy. Mössbauer spectra recorded in the temperature range of 78–300 K were analyzed using a hyperfine field distribution method. Additionally, the spectra recorded on the Cr3%Mn sample were analyzed in terms of three sextets. Derived therefrom values of a center shift, CS, were fitted to the Debye model yielded values of the Debye temperature, for Cr and for Cr3%Mn. The difference in the -value can be regarded as evidence that a spin-phonon coupling is different for the incommensurate and commensurate antiferromagnetic magnetic structure of chromium.

Mineral Composition Evaluation in Energy Drinks Using ICP OES and Chemometric Tools.

This study reports the simultaneous determination of the total concentrations of Al, Ca, Cr, Cu, Fe, K, Mg, Mn, Na, Ni, P, and Zn in17 samples of commercial energy drinks through inductively coupled plasma optical emission spectrometry and multivariate methods, such as Pearson correlation and principal component analysis (PCA), in order to conduct a more thorough evaluation of the original data. The samples studied were stored in two types of containers (polyethylene terephthalate bottles and aluminum cans) and purchased in the city of Belém (State of Pará, Brazil). The results showed high Na content in energy drinks, followed by K, Ca, and Mg. The accuracy of the optimized method was evaluated with the certified reference materials to assess trace elements in water (NIST 1643e); the resultant recoveries varied from 83 to 105%. Energy drinks stored in cans presented higher levels of aluminum and magnesium, while those bottled in polyethylene terephthalate bottles had a higher K content. There were significant differences between the observed Na concentrations and the values dictated on the drink package. Furthermore, PCA explained 70.38% of the total variance, allowing for an evaluation of the degree of similarity between the energy drinks studied and showing that the main contributions to the formation of groups are related to Fe, Na, Mg, and Zn contents. These results will be used to better understand the distribution of inorganic elements contained in energy drinks.

Effects of Cr addition and cold pre-deformation on the mechanical properties, damping capacity, and corrosion behavior of Fe–17%Mn alloys

The effects of Cr addition and cold pre-deformation on the microstructure, damping capacity, and corrosion behavior of Fe–Mn damping alloys were investigated. The mechanical properties were also analyzed. Results showed that cold pre-deformation narrowed the widths of the γ and ε phases, and promoted the γ → ε transformation as well as the reverse transformation. These increased the stacking fault probability and damping capacity. G-L plots illustrated cold pre-deformation can promote micro plastic deformation at high strain amplitudes. Although the Cr addition raised the stacking fault energy and moderately decreased the damping capacity, this addition increased the corrosion resistance because of the more stable and uniform corrosion product layer. The simultaneous application of cold pre-deformation and Cr addition led to ε → α′ transformations, which are beneficial for elongation but harmful for damping capacity. Additionally, the cold pre-deformation and Cr addition also affected the phases distribution, influencing the mechanical properties of the Fe–Mn samples. It can be concluded that Fe–17%Mn–5%Cr-10% materials are a good choice for reduction of noise and vibration in mechanical devices adverse because of its excellent elongation, good corrosion resistance, medium strength and high damping capacity.

Electrical, photoluminescence and ferromagnetic characterization of pure and doped ZnO nanostructures

The structural, electrical, optical, and magnetic properties of Zn0.95M0.05O samples (M = Zn, Ni, Cu, Fe, and Mn) are investigated. X-ray diffraction pattern revealed pure hexagonal wurtzite structure for all samples with an (210) additional peak formed only at 2 ~ 43.5° for Ni sample. The average crystalline diameter decreased from 20 nm for ZnO to 11.35 nm by the dopants, while the lattice and U parameters are nearly unchanged. Furthermore, the nonlinear coefficient and breakdown field are increased from 370.37 and 21.91 for ZnO up to 2291.67 and 55.96 by the dopants. The electrical conductivity of the upturn region is also increased by the dopants as compared to ZnO. There are two different values of the energy bandgap for each sample. The first gap is called fundamental gap Egh and its value above 3 eV, while the second gap is called optical gap EgL and its value below 2.6 eV. On the other hand, the UV band edges of photoluminescence intensity are 394, 402, 372, 390, and 404 nm, for Zn, Ni, Cu, Fe, and Mn samples. The Green shift is only recorded for Cu sample at 562 nm corresponding to 2.21 eV energy gap. The exciton energy, loss factor tan δ, and (N/m*) parameter are generally decreased by the dopants and follow the order Ni, Cu, Fe, Mn, and Zn, while lattice dielectric constant and inter-atomic distance are increased and follow the orders Zn, Mn, Fe, Cu, and Ni, and Zn, Ni, Cu, Mn, and Fe, respectively. Magnetization curves revealed clear room temperature ferromagnetism (RTFM) for Mn, Ni, and Fe samples, while they are showed weakly RTFM for Zn and Cu samples. Saturated magnetization Ms, remnant magnetization Mr, magnetization width, magnetic moment, coercivity of the field, and magneto-crystalline anisotropy factor are also affected by the dopants. Our results are discussed in terms of oxygen vacancies, valance state, and recombination of carriers, exhibited by the dopants to ZnO, rather than individual RTFM.

Studying the Thermal Neutron Spectrum of the W–Be Photoneutron Source at the Institute for Nuclear Research, Russian Academy of Sciences

The possibility is considered of reconstructing the thermal neutron flux density of a W–Be photoneutron source via neutron activation analysis of Ag, Mg, Fe, Mn, and Ti samples. The use of a simple function in the form AE−B describing the thermal region of the spectrum is discussed as an example of reconstruction. The dependence of the reaction rates’ deviation from the ones calculated on the parameters of the approximating function is investigated. The convergence of the reconstruction results as the number of experimental data grows is obtained. This means of recovery can be used for operational measurements of the thermal neutron flux density of the photoneutron source and to optimize the parameters of the source.

Raman spectra of natural manganese oxides

AbstractManganese oxides occur typically as cryptocrystalline and fine‐grained mixtures of different Mn‐phases, carbonates, silicates, and Fe oxides/hydroxides; thus their characterization by standard methods, such as X‐ray diffraction, is extremely challenging. These materials have been widely used in various applications over the millennia, for example, in art works as pigments for pottery, mural paintings, stained glass, and recently, as nanostructured materials with very attractive physicochemical properties. Furthermore, they are important geomaterials that could play a key role in environmental applications, by controlling the partitioning of arsenic and heavy metals between rocks, soils, and aqueous systems. Raman spectroscopy, which is a punctual and nondestructive technique, has been widely used to characterize these materials. However, literature data are often conflicting and contradictory, usually not allowing a proper identification of the Mn species. In this work, we characterize the most common natural manganese oxides by combining X‐ray powder diffraction, Fourier‐transform infrared spectroscopy, and Raman spectroscopy. Our data show that some manganese oxides have characteristic Raman spectra and can be easily recognized by using Raman spectroscopy alone, whereas integration of Raman data with other techniques is mandatory to characterize minerals that have almost identical Raman spectra. With this respect, Raman spectroscopy is the only technique allowing an easy discrimination between hollandite [Ba(Mn4+6,Mn3+2)O16] and cryptomelane [K(Mn4+7,Mn3+)O16]. The final goal of this work is to provide reference Raman spectra, acquired on previously well‐characterized Mn samples to facilitate the application of Raman spectroscopy in the study of these geomaterials.

Connection between Unusual Lattice Thermal Expansion and Cooperative Jahn-Teller Effect in Double Perovskites LaPbMSbO6 (M = Mn, Co, Ni).

Lattice thermal expansion (LTE) has been investigated in double perovskites LaPbMSbO6 (M = Mn, Co, Ni). Ordinary LTE behavior with good thermal stability is identified for the Mn sample, whereas unusual LTE with a preferably expanded interplanar distance of (040) is revealed for Co and Ni samples. Temperature-dependent X-ray diffraction patterns ( T-XRD), Raman spectra ( T-Raman), and specific heat capacities ( T- Cp) consistently indicate that a rare isostructural displacive phase transition (IDPT) with a second-order phase transition nature is predominant near the critical temperature. Refinements of neutron powder diffraction (NPD) and in situ T-XRD data present temperature-sensitive bond parameters which are relevant to planar oxygen O1. X-ray photoelectron spectra (XPS) further confirm the Jahn-Teller (J-T) activated Co2+ (HS) or Ni3+ (HS/LS) cations at the B-site sublattice. This unusual LTE behavior could be understood by the cooperative J-T effect contributed by a Pb2+ ion and Co2+/Ni3+ ion from A- and B-site sublattices, respectively. The importance of 6s(Pb)-2p(O)-3d(Co/Ni) extended orbital hybridization on affecting thermal expansion behavior is highlighted on the basis of temperature-induced phonon mode softening. This study presents a microscopic description of connection between anisotropic thermal expansion and a cooperative J-T effect, which inspired exploration of thermal-mechanical coupled functional materials based on LaPbMSbO6 double perovskites.

Structural, Electrical, and Magnetic Properties of $\text{Bi}_{0.90}\text{Nd}_{0.10}\text{Fe}_{0.98}TM_{0.02}\text{O}_{3}$ ($TM= \text{Mn}$, Co, Ni, and Cu) Materials

Pure BiFeO3 (BFO) and Bi 0.90 Nd 0.10 Fe 0.98 TM 0.02 O 3 (TM = Mn, Co, Ni, and Cu) materials have been synthesized by the sol-gel method. Effects of codoping Nd and transition metal (TM) on the structural, electrical, and magnetic properties of BFO were investigated by X-ray diffraction (XRD), energy dispersive X-ray spectroscopy, scanning electron microscope (SEM), vibrating sample magnetometry, polarization vs. electric field hysteresis loops (P-E), and complex impedance spectra measurements. A distortion of crystal structure, in which lattice parameters a and c decreased in all codoped samples, was measured by XRD. SEM images showed a significant reduction of average grain size and an obvious change in surface morphology with Nd and TM codoping in BFO. Codoped samples demonstrated various improvements in ferroelectric and ferromagnetic properties, most notably for codoped (Nd and TM) samples. Saturation magnetization (Ms) and saturation dielectric polarization (Ps) increased from Ms = 0.060 emu/g, Ps = 1.03 μC/cm 2 for pure BFO to Ms = 0.411 emu/g, Ps = 11.08 μC/cm 2 for a codoped (Nd and Mn) sample. Our results show that Mn is the best TM for codoping with Nd in BFO to improve its multiferroic properties.

Structural and magnetic characterizations of Co2MnO4 doped with Cr, Mn, Fe and Cu

The structural and magnetic properties of Co2-xMxMnO4 (M= Cr, Mn, Fe and Cu) samples are investigated. Element substitution does not change the cubic lattice structure within a range of concentrations. There is a structural transition from cubic to tetragonal with the excessive addition of Mn atoms. The site preference of transition metal atoms influences the interatomic interactions in the oxide system. The interatomic interactions of Co2MnO4 and CoMn2O4 samples are analyzed though ZFC/FC curves, the transition temperatures of which are attributed to the combined effect of magnetic interactions in different sublattices. The magnetic structure is restructured by atomic substitution and site preference, resulting in the compositional dependence of magnetic properties.

Specific Effect of Trace Metals on Marine Heterotrophic Microbial Activity and Diversity: Key Role of Iron and Zinc and Hydrocarbon-Degrading Bacteria.

Marine microbes are an important control on the biogeochemical cycling of trace metals, but simultaneously, these metals can control the growth of microorganisms and the cycling of major nutrients like C and N. However, studies on the response/limitation of microorganisms to trace metals have traditionally focused on the response of autotrophic phytoplankton to Fe fertilization. Few reports are available on the response of heterotrophic prokaryotes to Fe, and even less to other biogeochemically relevant metals. We performed the first study coupling dark incubations with next generation sequencing to specifically target the functional and phylogenetic response of heterotrophic prokaryotes to Fe enrichment. Furthermore, we also studied their response to Co, Mn, Ni, Zn, Cu (individually and mixed), using surface and deep samples from either coastal or open-ocean waters. Heterotrophic prokaryotic activity was stimulated by Fe in surface open–ocean, as well as in coastal, and deep open-ocean waters (where Zn also stimulated). The most susceptible populations to trace metals additions were uncultured bacteria (e.g., SAR324, SAR406, NS9, and DEV007). Interestingly, hydrocarbon-degrading bacteria (e.g., Thalassolituus, Marinobacter, and Oleibacter) benefited the most from metal addition across all waters (regions/depths) revealing a predominant role in the cycling of metals and organic matter in the ocean.

Phase transition, microstructure and electrical properties of K1‐xNaxNbO3‐based ceramic sintered in reducing atmosphere

AbstractLead‐free 0.955K1‐xNaxNbO3‐0.045Bi0.5Na0.5ZrO3+0.4% mol MnO ceramics (Abbreviated as K1‐xNxN‐0.045BNZ+0.4Mn) were prepared by a conventional solid‐state sintering method in a reducing atmosphere (oxygen partial pressure : 1 × 10−11 MPa). All K1‐xNxN‐0.045BNZ+0.4Mn samples show a pure perovskite structure with a polymorphic phase boundary (PPB) composed of rhombohedral (R) and tetragonal (T) phases. A high Na/K ratio and a low Na/K ratio can both induce an increase in the rhombohedral phase. The reverse piezoelectric coefficient and its temperature stability in K1‐xNxN‐0.045BNZ+0.4Mn ceramics can be improved by controlling the Na/K ratio. The increase in the Na/K ratio from x = 0.46 to x = 0.56 can decrease the A‐site cation vacancies. The activation energy of the grain is higher than that of the grain boundary due to the accumulation of oxygen vacancies at the grain boundary. K1‐xNxN‐0.045BNZ+0.4Mn ceramics with excellent piezoelectric properties (quasi‐static piezoelectric coefficient d33 = 326 pC/N, and = 472 pm/V at Emax = 25 kV/cm) were obtained at x = 0.52.

Thermoelectric Properties of Co- and Mn-Doped Al2Fe3Si3

Al2Fe3Si3 is a promising semiconductor for application as an environmentally friendly thermoelectric material. Its intrinsic carrier concentration is 5 × 1019 cm−3 and shows p-type conduction. In this article, we report on the thermoelectric properties of carrier-doped Al2Fe3Si3. Co or Mn was substituted for Fe for electron or hole doping, respectively. Al2Fe3−xMxSi3 (M=Co or Mn; x = 0.1–1.0 for Co and 0.1–0.3 for Mn) samples were synthesized by arc melting followed by spark plasma sintering and heat treatment. The Co- and Mn-doped samples displayed Hall carrier concentrations of 1.4 × 1020 cm−3 to 5.1 × 1020 cm−3 for n-type and 1.3 × 1020 cm−3 to 1.3 × 1021 cm−3 for p-type conduction. The n-type Al2Fe3Si3 exhibited a higher absolute value of Seebeck coefficient and lower Hall carrier mobility than p-type Al2Fe3Si3 at the same carrier concentration. The power factor increased with increasing carrier concentration for n-type conduction, and reached 0.65 × 10−3 W/mK at 520 K. On the other hand, the power factor for p-type Al2Fe3Si3 was not enhanced with increasing carrier concentration. The maximum ZT value for Co-substituted Al2Fe3Si3 was 0.09 at 600 K, which is 50% higher than that of pure Al2Fe3Si3.

Comparative measurement of metal contents in raw and cooked rice samples prepared in different rice cookers using SR-XRF and health risk assessment

Rice is full of nutrients that are essential to humans, however, exposure to the high metal contents in rice could also pose potential health risks to consumers. This work aimed to investigate this safety concern using the synchrotron radiation X-ray fluorescence spectrometry (SR-XRF), which is considered one of the most advanced and accurate elemental analysis techniques, to quantify metal contents, namely Fe, Zn, Cu, Ca, and Mn, in raw and cooked rice samples in order to assess the potential health risks associated with rice consumption. The results indicated that cooked rice samples had lower Fe and Ca but higher Zn, Cu, and Mn contents than raw rice samples (p < 0.05). The highest changes in metal contents were the decrease in the Ca content, which was reduced up to 8.5 times in rice samples cooked with running water and was lower than the detection limit (< 2.0 mg kg−1) in rice samples cooked with de-ionized water. When comparing the average estimated weekly intake with the available provisional tolerable weekly intake (PTWI) issued by the World Health Organization (WHO), the results showed that Fe, Zn, and Cu had lower average estimated weekly intake values than the PTWI levels. In terms of chronic, non-carcinogenic health risk assessment, the individual hazard quotient (HQ) of each metal of interest was less than the limit (1.0). However, the hazard index (HI), which combined all HQ values, was 1.15, indicating possible chronic health risks from rice consumption. The results obtained from this work suggest that further investigation is needed to fully understand and to promote awareness of the health risks caused by rice consumption.

Synthesis and Characterization of Nanosized Cobalt Manganese Alloys

Co–Mn alloy nanoparticles are synthesized by chemical route by the decomposition of metal chlorides by sodium borohydride using oleic acid as the capping agent. SEM, TEM and XRD are used to determine structural and morphological properties of the samples. From XRD spectra analysis, it is confirmed that the sample contains cobalt–manganese alloy. Transmission Electron Microscopy (HR-TEM) is used to estimate the particle size of the Co–Mn sample where a bimodal particle size distribution with one maximum at (3.5 ± 1.8) nm and another maximum at (7.6 ± 2.5) nm is observed. Magnetic investigation employed by Vibrating Sample Magnetometry (VSM) shows that the samples are magnetic with saturation magnetization of 0.018 emu/g for the prepared sample and 0.457 emu/g for the annealed sample. The nature of chemical conjugation of Co–Mn nanoparticles and oleic acid is analyzed by Fourier transform infrared spectroscopy. Thermogravimetric measurements of Co–Mn indicate exothermic peaks at 545 K and 723 K revealing the structural transition from amorphous phase to crystallined form. The chemical composition of the sample is verified using EDX spectra.

Photocatalytic and photo-induced disinfection activities of sol-gel synthesized CeO2–SnO2:TM (TM= Co, Ni and Mn) nanocomposites: Relation between physical properties and their performance

CeO2-SnO2 and transition metals (Co, Ni and Mn)-doped CeO2–SnO2 nanoparticles (NPs) were prepared by organic sol-gel route. X-ray diffraction analysis and Williamson–Hall isotropic strain method indicated that the crystallite size of cubic fluorite structure decreased by transition metals doping from 12.6 to 4.7 nm. The optical bandgap of CeO2–SnO2 nanocomposites decreased from 3.21 to 2.91 eV for CeO2–SnO2:Mn sample. The blue-green PL emission peak of NPs enhanced with doping due to increased Ce3+ and oxygen vacancies content. Photocatalytic degradation of rhodamine B (RhB) in aqueous solution under UV irradiation in the presence of CeO2–SnO2 NPs was investigated. Transition metals doping improved The photodegradation ratio of CeO2–SnO2 and the CeO2–SnO2:Mn nanoparticles had the highest efficiency compared to other samples. More interesting, evaluation of antibacterial and photo-induced disinfection activity of CeO2–SnO2:TM NPs against clinically important bacteria manifested the highest antibacterial potential for CeO2–SnO2:Mn compared to the other NPs. It is therefore proposed that enhanced oxygen vacancies as well as high surface area assist to produce reactive oxygen sites (ROHs) which are accountable for photocatalytic and photo-induced disinfection activities.

Austenite stability and mechanical properties of nanocrystalline Fe–Mn alloy fabricated by spark plasma sintering with variable Mn content

The effects of Mn content on the austenite stability and mechanical properties of nanocrystalline Fe–(4–10)%Mn alloys were investigated by means of micrograph observation, X-ray analysis, and mechanical testing. The Fe–Mn alloy samples with nanosized crystallite were successfully fabricated by spark plasma sintering because of an extremely short densification time, not only to reach the theoretical density value but also to prevent grain growth. The increased Mn content reduced the crystallite size and increased the volume fraction of austenite. In particular, the volume fractions of austenite in the nanocrystalline Fe–Mn samples were more than approximately four times higher than the equilibrium values. The progress of the compressive deformation increased the volume fraction of strain-induced martensite from the austenite decomposition. The kinetics of the strain-induced martensite formation were evaluated using the empirical equation considering the austenite stability factor. Both larger Mn content and smaller crystallite resulted in the increase in the austenite stability, contributing to not only a higher volume fraction of austenite after sintering, but also an improvement in its mechanical properties during the deformation.

Sintering time optimization on red photoluminescence properties of manganese-doped boron carbon oxynitride (BCNO:Mn) phosphor

The effect of sintering time to the transient nature and optimization of red photoluminescence manganese-doped boron carbon oxynitride (BCNO:Mn) phosphor was investigated. The BCNO:Mn samples were synthesized using a facile urea-assisted combustion route involving boric acid, citric acid, manganese salt and urea. The optimized intensity of the dual peak emission at 420 nm (blue emission) and 630 nm (red emission) in the photoluminescence (PL) spectrum could be achieved by controlling the sintering time of the BCNO:Mn. The BCNO:Mn samples in high-crystalline form was found to be in a cubic and hexagonal structure. Based on the PL analysis, it is suggested that the BCNO:Mn symmetric band at 630 nm can be attributed to the 4T1(4G)—6A1(6S) transition absorption of Mn2+ ions into the hexagonal structure. Microstructure analysis showed an irregular and agglomerated shape of the BCNO:Mn sample.

Rapid Microwave Preparation and Composition Tuning of the High-Performance Magnetocalorics (Mn,Fe)2(P,Si).

Rapid preparation utilizing assisted microwave heating permits significantly shorter preparation times for magnetocaloric compounds in the (Mn,Fe)2(P,Si) family, specifically samples of (Mn,Fe)2-δP0.5Si0.5 with starting compositions of δ = 0, 0.06, and 0.12. To fully understand the effects of processing and composition changes on structure and properties, these materials are characterized using synchrotron powder diffraction, neutron powder diffraction, electron microprobe analysis (EMPA), X-ray fluorescence (XRF), and magnetic measurements. The diffraction analysis reveals that increasing δ results in decreasing amounts of the common Heusler (Mn,Fe)3Si secondary phase. EMPA shows (Mn,Fe)2(P,Si) in all three samples to be Mn and P rich, whereas XRF demonstrates that the bulk material is Mn rich yet P deficient. Increasing δ brings the Mn/Fe and P/Si ratios closer to their starting values. Measurements of magnetic properties show an increase in saturation magnetization and ordering temperature with increasing δ, consistent with the increase in Fe and Si contents. Increasing δ also results in a decrease in thermal hysteresis and an increase in magnetic entropy change, the latter reaching values close to what have been previously reported on samples that take much longer to prepare.

Design considerations for reducing sample loss in microfluidic paper-based analytical devices

The field of microfluidic paper-based analytical devices (μPADs) is most notably characterized by portable and low-cost analysis; however, struggles to achieve the high sensitivity and low detection limits needs required for many environmental applications hinder widespread adoption of this technology. Loss of analyte to the device material represents an important problem impacting sensitivity. Critically, we found that at least 50% of a Ni(II) sample is lost when being transported down a 30 mm paper channel that is representative of structures commonly found in μPADs. In this work, we report simple strategies such as adding a waste zone, enlarging the detection zone, and using an elution step to increase device performance. A μPAD combining the best performing functionalities led to a 78% increase in maximum signal and a 28% increase in sensitivity when transporting Ni(II) samples. Using the optimized μPAD also led to a 94% increase in maximum signal for Mn(II) samples showing these modifications can be applied more generally.

Influence of Ga vacancies, Mn and O impurities on the ferromagnetic properties of GaN micro- and nanostructures

We present a study of the influence of gallium vacancy (VGa) point defects on the ferromagnetic properties of GaN:Mn and GaN:Mn,O micro- and nanostructures. Results demonstrate that the generation of these point defects enhances the ferromagnetic signal of GaN:Mn microstructures, while incorporation of oxygen as an impurity inhibits this property. XPS measurements revealed that Mn impurities in ferromagnetic GaN:Mn samples mainly exhibit a valence state of 2+. Cathodoluminescence (CL) spectra from Mn-doped GaN samples displayed emissions centered at about 1.97 eV, attributed to transitions between the 4T1-6A1 states of the Mn2+ d orbitals, and emissions centered at 2.45 and 2.9 eV, associated with the presence of VGa. CL measurements also revealed a blue shift of the GaN band-edge emission generated by the expansion of the wurtzite lattice due to Mn incorporation, which was confirmed by XRD measurements. These latter measurements also revealed an amorphization of GaN:Mn due to the incorporation of oxygen as impurities. The GaN:Mn samples were synthesized by thermal evaporation of GaN and MnCO3 powders onto Ni0.8Cr0.2/Si(100) in a horizontal furnace operated at low vacuum. The residual air inside the system was used as a source of oxygen during the synthesis of Mn and O co-doped GaN nanostructures. Mn and O impurities were incorporated into the nanostructures at different concentrations by varying the growth temperature. Energy Dispersive Spectroscopy, XRD, and XPS measurements confirmed that the obtained samples predominantly consisted of GaN.