Mn In Samples Research Articles

Attestation in self-propagating combustion approach of spinel AFe2O4 (A = Co, Mg and Mn) complexes bearing mixed oxidation states: Magnetostructural properties

Spinel type nano-sized ferrite compounds AFe2O4 (A=Co, Mg and Mn) have been successfully prepared by self-propagating combustion method using glycine as fuel at 400°C under air atmosphere for 4h. The crystal structure, chemical composition, morphology and magnetic properties of the synthesized samples were characterized by X−ray diffraction, Fourier transform infrared spectroscopy, X−ray photoelectron spectroscopy, Energy dispersive X−ray, Scanning and Transmission electron microscopy and vibrating sample magnetometer. The chemical reaction and role of fuel on the nanoparticles formation were discussed. The XRD pattern of the synthesized samples shows the formation of pure phase with average crystallite size of 97, 57 and 98nm from Scherrer formula and 86, 54 and 87nm from Williamson and Hall (W–H) formula respectively. FTIR absorption spectra revealed that the presence of strong absorption peaks near 400–600cm−1 corresponds to tetrahedral and octahedral complex of spinel ferrites. The relative concentrations of electronic states of elements such as cobalt (Co2+ and Co3+), iron (Fe2+ and Fe3+) and manganese (Mn2+ and Mn3+) oxidation states were studied from XPS and it is found that 55% of Fe ions are in Fe2+ state and the remaining is in Fe3+ state and thus the cationic distribution of Fe ions occurred in both tetrahedral and octahedral sites. SEM analysis indicates the presence of pore like morphology which is nearly homogenous because of combustion process. EDS analysis confirms the presence of elements in the ferrite samples. By replacing the active ‘A’ site cations in AFe2O4 (A=Co, Mg and Mn) samples show the different magnetic properties. The parameters like saturation magnetization, coercivity and remnant magnetization obtained from M−H loops are studied in room temperature.

PVC 여과지를 이용한 금속 분석방법에 대한 정확도와 정밀도 평가

Objectives: This study was conducted to evaluate the accuracy and precision of airborne metal analysis using polyvinyl chloride(PVC) membrane filter by pretreatment methods. Methods: A total of 75 spiked PVC samples for Cr, Fe and Mn ranged from 6 ug/sample to 40 ug/sample were used to evaluate recovery rates for three pretreatment methods: acid extraction, hot plate ashing and microwave digestion. For Mn, an additional 75 spiked mixed cellulose ester(MCE) membrane filters were analysed to compare the recovery rates of PVC samples. All samples were analysed with an inductively coupled plasma optical emission spectrometer(ICP-OES) and manganese samples were additionally analyzed by atomic absorption spectrometer(AAS). Results: The overall mean recovery rates of PVC samples for Cr, Fe and Mn were 90% or higher regardless of pretreatment methods, but there were statistically significant differences in recovery rates for Cr(p<0.05) and Mn(p<0.01) samples by pretreatment methods. The biases and the coefficient variations of PVC samples for three metals pretreated with three kinds of pretreatment methods ranged from 1.7% to 4.7% and from 1.6% to 6.5%, respectively. The manganese PVC samples pretreated by microwave digestion and analyzed with ICP-OES had the lowest bias at 1.9% and also showed lower bias than the bias for MCE samples, 2.7%. Conclusions: In order to accurately analyze the metals sampled with PVC membrane filters, microwave digestion and ICP-OES can be recommended.

Tunable exchange bias in dilute magnetic alloys – chiral spin glasses

A unidirectional anisotropy appears in field cooled samples of dilute magnetic alloys at temperatures well below the cusp temperature of the zero field cooled magnetization curve. Magnetization measurements on a Cu(13.5 at% Mn) sample show that this anisotropy is essentially temperature independent and acts on a temperature dependent excess magnetization, ΔM. The anisotropy can be partially or fully transferred from being locked to the direction of the cooling field at lower fields to becoming locked to the direction of ΔM at larger fields, thus instead appearing as a uniaxial anisotropy. This introduces a deceiving division of the anisotropy into a superposition of a unidirectional and a uniaxial part. This two faced nature of the anisotropy has been empirically scrutinized and concluded to originate from one and the same exchange mechanism: the Dzyaloshinsky-Moriya interaction.

The characterization of near‐surface defects evolved on aluminum–manganese alloys during hot rolling

Hot rolling laboratory experiments were performed on an Al–Mn alloy, utilizing a rolling tribo‐simulator to characterize the evolution of near‐surface defects induced by tribological interactions between the work roll and alloy surfaces. A ten pass hot rolling schedule was conducted on Al–Mn samples using an AISI 52100 work roll polished to a surface roughness (Ra) of 0.01 μm. Micro‐cracks formed on the alloy surfaces at the first pass were observed to initiate at grain boundaries and propagate less than 1.5 μm deep into the subsurface region. The faces of the micro‐cracks in the subsurface region were observed to be covered with MgO. The surface of the samples were observed to possess a top 90‐nm‐thick oxide‐rich layer, which was mostly composed of MgO. MgAl2O4 and Al2O3 were also observed on the alloy surface at this stage of rolling. After ten passes, near‐surface features on the Al–Mn alloy samples included MgO‐rich islands and transverse cracks. Cracks extended more than 2 μm deep into the subsurface. Crack faces were covered with surface deformation induced crevices as well as MgO. The near‐surface was also composed of nano‐crack induced damaged areas, filled with porous nanocrystalline oxides. These damaged areas extended 0.5 μm into the subsurface region beneath a 60‐nm‐thick MgO film. The nanocrystalline oxide layers possessed embedded aluminum nano‐particles. The microstructure of the near‐surface layer suggests that magnesium diffusion to the free surfaces and crack formation play an important role in its evolution. Copyright © 2015 John Wiley &amp; Sons, Ltd.

Effect of Mn and Ni codoping on ion dynamics of nanocrystalline cobalt ferrite: A structure property correlation study

Effect of Mn and Ni codoping on structure, optical and electrical properties of cobalt ferrite nanoparticles prepared by coprecipitation route have been investigated in detail. DSC-TGA, XRD and HRTEM studies have been explored to confirm the phase purity and structure. Most possible cation distribution as estimated by Rietveld analysis suggests the formation ofmixed spinel ferrite phase by the migration of Co2+ ions from B site to A site and hence Fe3+ ions from A site to B site in different amounts due to the doping of Mn and Ni ions. UV–vis study reveals a red shift for Mn and Mn-Ni co-doped samples while a blue shift was observed in case of Ni doping. Conductivity spectra follows the double power law and the modulus spectroscopy study indicates the coexistence of two incomplete relaxation processes in the system that arises due to the co-contribution from both grain and grain boundary which were thoroughly confirmed by complex impedance analysis. Improvement in the dielectric properties in the materials due to doping could be beneficial for device applications.

In vitro Binding Capacity of Wheat and Barley for Mn, Zn, Cu and Fe

This study was carried out to determination of in vitro binding capacity of wheat and barley for Mn, Zn, Cu and Fe. For this reason wheat and barley were chemical analyzed for moisture, protein, ash, ether extract, total carbohydrate, NDF, ADF, ADL, crude fiber, viscosity, cellulose, hemicelluloses, total dietary fiber, and endogenous minerals. Mineral binding capacity of two samples for Mn, Zn, Fe, and Cu under sequential simulated physiological conditions of the stomach, small intestine, and colon was investigated and compared. Barley showed the higher mineral binding capacity in small intestine. Among the minerals, Fe exhibited the highest percentage of binding under the simulated physiological conditions of the small intestine and the lowest percentage of removing occurred in the stomach for both cereals. Cereals had an affinity for Fe&gt;Cu&gt;Zn&gt;Mn.

Incorporation of Mn inAlxGa1−xNprobed by x-ray absorption and emission spectroscopy, high-resolution microscopy, x-ray diffraction, and first-principles calculations

Synchrotron radiation x-ray absorption and emission spectroscopy techniques, complemented by high-resolution transmission electron microscopy methods and density functional theory calculations are employed to investigate the effect of Mn in Al$_{x}$Ga$_{1-x}$N:Mn samples with an Al content up to 100%. The atomic and electronic structure of Mn is established together with its local environment and valence state. A dilute alloy without precipitation is obtained for Al$_{x}$Ga$_{1-x}$N:Mn with Al concentrations up to 82%, and the surfactant role of Mn in the epitaxial process is confirmed.

Local structure and photoluminescence properties of nanostructured Zn1‐xMnxS material

AbstractZinc sulfide (ZnS) pure or doped has received remarkable attention because of fundamental properties, versatility and potential for several technological applications as luminescent material. In this study, the local structure and photoluminescence properties of nanostructured Zn1‐xMnxS samples have been characterized. X‐ray diffraction results show that ZnS:Mn samples crystallized completely without the presence of secondary phases and the diffraction patterns correspond to the cubic zinc blende. Theoretical and experimental XANES (X‐ray absorption near edge structure) spectra at Zn K‐edge suggest the incorporation of Mn atoms into the ZnS host and indicate the occurrence of Zn and S vacancies, which are confirmed by EXAFS (extended X‐ray absorption fine structure) fit results. These vacancies can be related to a red‐shift observed in the peak emission of photoluminescence spectrum for ZnS sample, which is centered at ∼ 504 nm. As the Mn content increases, a yellow‐orange emission centered at ∼ 590 nm can be observed besides the blue‐green emission, which is associated with the 4T1–6A1 transition within the 3d shell of Mn2+. (© 2015 WILEY‐VCH Verlag GmbH &amp; Co. KGaA, Weinheim)

Study of the first paramagnetic to ferromagnetic transition in as prepared samples of Mn–Fe–P–Si magnetocaloric compounds prepared by different synthesis routes

Magnetocaloric materials with composition of Mn1.3Fe0.65P0.5 Si0.5 have been prepared by ball milling and solid-state reaction methods and consolidated using powder annealing, and conventional and spark plasma sintering. Magnetic and calorimetric measurements show remarkable differences upon first cooling, and slight differences on second and further coolings between the samples prepared by different synthesis routes. Further measurements using Hall probe imaging in high magnetic field have been also carried out. As-prepared samples have been cooled down just above the critical temperature, and the first phase transition has been induced by application of a magnetic field. Bulk samples show staircase isothermal magnetization curves whereas powders show smoother transition curves.

Polaron response dominated multiferroic property in 12R-type hexagonal Ba(Ti1/3Mn2/3)O3-δ ceramics

We report the multiferroic properties of 12R-type hexagonal Ba(Ti1/3Mn2/3)O3-δ found in Mn-doped BaTiO3 series samples. Hysteresis measurements reveal the coexistence of weak ferromagnetism and ferroelectricity at room temperature. Furthermore, frequency-driven dynamic ferroelectric phase transition is disclosed around a critical frequency of 220 Hz. Analyses on the dielectric relaxation, leakage current, crystal structure, and magnetic susceptibility lead us to conclude that the response of polarons dominates the observed physical properties, and the dynamic phase transition may ascribe to the response mode changes of the localized electrons. More importantly, we figure out the crucial factors leading to difference of the ferroelectric and magnetic properties of the 12R-type Ba(Ti1/3Mn2/3)O3-δ samples from that of the 6H-type Ba(Ti1-xMx)O3-δ (M = Fe, Mn) samples.

Screening of Metal Oxidesfor Hg0Capture

Fossil fuel related industriesare the major anthropogenic sources of Hg0 emission. Due to awareness of the detrimental impact, there is an increasing interest in discovering potential materials for Hg0 removal. In this paper, the first-row transition metals (from V to Zn), Mo and rare earth metals (La and Ce) in the oxidation states supported by γ-Al2O3werepreparedand studied as potential candidates for Hg0 capture. Based on evolution of the parameters of enthalpies (ΔH), Gibbs free energy (ΔG), adsorption peaks (Ta, peak), maximumHg0 capture efficiencies (μmax) and activation energy (Ea)etc, the samples of Cr, Ni, Fe, Mn, Co, Ce and Cu showed better performancesfor Hg0 capture amongst the 11 metal oxides. The results also indicated that MoO3 has potential to promote Hg0 capture since the activation energy is relatively low. Consequently, most of the Mo-based binary metal oxides have relatively high Hg0 removal efficienciescoupled with lowactivation energies. Particularly, the binary metal oxides of CrMo, MnMo, CuMo, CeMo andCoMo could be selected as appropriate candidates for Hg0 capture within specifictemperature windows.

Superelastic anisotropy characteristics of columnar-grained Cu–Al–Mn shape memory alloys and its potential applications

Abstract The columnar-grained (CG) Cu–Al–Mn shape memory alloy samples possess a strong -oriented texture along the solidification direction (SD) and straight low-energy grain boundaries fabricated by unidirectional solidification technique. When the angle between tensile direction and the SD ranged from 0° to 90° at the tensile tests, the superelasticity of samples changed in a “V” shape and showed a large anisotropy. Meanwhile, the martensite transformation critical stress of the CG Cu–Al–Mn samples increased from 258.5 MPa for 0° to 521.9 MPa for 45°, and then decreased to 324.3 MPa. The large anisotropy of the superelasticity was attributed to the combined effects of grain orientation and grain boundaries, wherein the influence of the grain boundaries had an obvious dependence on orientation. The potential applications of CG Cu–Al–Mn alloys as anisotropic shock isolators and dampers in high rise buildings and precision instruments were also proposed.

Release of Potentially Toxic Elements From Industrial Sludge: Implications for Land Disposal

In recent years, rapid industrial development has led to an increase in various types of industrial waste generation in Vietnam. Potentially toxic elements (PTEs) can contaminate water resources when waste is not properly treated and/or stored in confined disposal facilities. This study characterizes the occurrence and leaching behavior of PTEs from industrial sludge under the influence of oxidation and pH with implications for open dump disposal. Environmental issues related to possible management options are also addressed. Sludge samples from industrial parks at Binh Duong and Dong Nai, Southern Vietnam, were oxidized under atmospheric conditions. The results indicate that Fe and Mn (both samples) and Cu, Ni, and Zn (Binh Duong sample) may pose a potential threat to the water quality for sludge dumped near water bodies. Therefore, we recommend avoiding uncontrolled upland disposal of such sludge. Some preliminary treatment to immobilize PTEs should be applied to the sludge originating from Binh Duong prior to upland disposal. A recovery of Ni and Zn from this sludge could be considered. For the less contaminated sludge from Dong Nai, beneficial use, such as land application for agricultural purposes, is a possible option.

The age of supergene manganese deposits in Katanga and its implications for the Neogene evolution of the African Great Lakes Region

Supergene manganese deposits commonly contain K-rich Mn oxides with tunnel structure, such as cryptomelane, which are suitable for radiometric dating using the 39Ar–40Ar method. In Africa, Mn deposits have been dated by this method for localities in western and southern parts of the continent, whereas only some preliminary data are available for Central Africa. Here we present new 39Ar–40Ar ages for Mn oxide samples of the Kisenge deposit, in southwestern Katanga, Democratic Republic of the Congo. The samples represent supergene Mn oxide deposits that formed at the expense of primary Paleoproterozoic rhodochrosite-dominated carbonate ores. Main phases of Mn oxide formation are dated at c. 10.5Ma, 3.6Ma and 2.6Ma for a core that crosses a mineralized interval. The latter shows a decrease in age with increasing depth, recording downward penetration of a weathering front. Surface samples of the Kisenge deposits also record a ≥c.19.2Ma phase, as well as c. 15.7Ma, 14.2Ma and 13.6Ma phases. The obtained ages correspond to distinct periods of paleosurface development and stability during the Mio-Pliocene in Katanga. Because Katanga is a key area bordered to the North by the Congo Basin and to the East by the East African Rift System, these ages also provide constraints for the geodynamic evolution of the entire region. For the Mio-Pliocene, the Kisenge deposits record ages that are not systematically found elsewhere in Africa, although the 10.5–11Ma event corresponds to a roughly simultaneous event in the Kalahari Manganese Field, South Africa. The rest of the Katanga paleosurface record differs somewhat from records for other parts of Africa, for which older, Eocene ages have been obtained. This difference is most probably related to the specific regional geodynamic context: uplift of the East African Plateau, with associated erosion, and the opening of the East African Rift System at c. 25Ma are events whose effects, in the study area, interfere with those of processes responsible for the development of continent-wide paleosurfaces.

Preparation by co-precipitation of Ce–Mn based catalysts for combustion of n-hexane

Catalysts for combustion of Mn mixed oxides with different Ce/Mn molar ratios ranging from 0.5 to 2, have been prepared by co-precipitation at constant pH with aging times of 4, 18 and 24h. XRD patterns of the mixed oxides showed the dominant presence of fluorite-like phase. The surface area of mixed oxides was always higher than their single oxide counterparts and their adsorption isotherm corresponding to type IV depicted a mesoporous surface. TPR profiles of mixed oxides shifted to lower temperatures with increasing content of Ce, revealing a strong metal interaction in composites. Ce–Mn samples exhibited higher activities than the corresponding simple oxides regardless of the aging time. Sample Ce0.67Mn0.33O2 with 24h of aging time showed the highest performance probably due to the presence of defect sites promoted by the incorporation of MnOx species into CeO2 structure, its highest surface area and best reducibility.

Effect of Mn content on structural, optical, opto-thermal and electrical properties of ZnO:Mn sprayed thin films compounds

Manganese-doped zinc oxide thin films (ZnO:Mn) at different percentages (0–3%) were deposited on glass substrates using a chemical spray technique. The effects of manganese element content on structural, optical, opto-thermal and electrical conductivity of ZnO:Mn thin films were investigated by means of X-ray diffraction, optical measurement, Photoluminescence spectroscopy and impedance spectroscopy. XRD analysis revealed that all films consist of single phase ZnO and were well crystallized in würtzite phase with the crystallites preferentially oriented towards (002) direction parallel to c-axis. Doping manganese resulted in a slight decrease in the optical band gap energy of the films and a noticeably change in optical constants. The UV peak positions for ZnO:Mn samples slightly red shift to the longer wavelength in comparison with the pure ZnO which can be attributed to the change in the acceptor level induced by the substitutional Mn2+ and the band-gap narrowing of ZnO with the Mn dopant. We have performed original AC and DC conductivity studies inspired from Jonscher and small polaron models. These studies helped establishing significant correlation between temperature and activation energy and Mn content. From the spectroscopy impedance analysis we investigated the frequency relaxation phenomenon and the circuit equivalent circuit of such thin films. Finally, all results have been discussed, as an objective of the actual work, in terms of the manganese doping concentration.

Physico-chemical Properties of Effluents Discharged from Different Industries of Gazipur, Bangladesh and its Suitability for Agricultural Land

The study was conducted to assess physical parameters, major ionic constituents and trace metals content at Gazipur area to know the quality of effluent during March in 2013 for irrigation usage. The pH of collected effluent samples were almost neutral but in case of TDS values all the samples were suitable for irrigation where considering EC values almost harmful for irrigation. The anion i.e. in case of CO 3 , SO 4 and PO,sub>4 all the collected effluent samples were suitable for irrigation but in case of almost Cl values and all HCO 3 values unsuitable for irrigation. Similarly, the cation i.e. in case of Na, Mg, Ca and K all the collected effluent samples were suitable for irrigation. Among the studied trace metals (Fe, Zn, Cu, Pb, Cd and Mn) all of the collected effluent samples were suitable for irrigation except two samples for Mn and Cu. On the other hand, in case of SAR most of the samples were excellent category but in case of SSP most of the samples were graded as doubtful and in case of RSC and hardness most of the samples were unsuitable class for irrigation purposes. So to protect the agricultural land whole of the study area a pollution free technology such as Effluent Treatment Plants (ETP) to each industry should be established. DOI: http://dx.doi.org/10.3329/jesnr.v7i1.22165 J. Environ. Sci. & Natural Resources, 7(1): 157-167 2014

Ex-situ7Li MAS NMR Study of Olivine Structured Material for Cathode of Lithium Ion Battery

<TEX>$^7Li$</TEX> nuclear magnetic resonance (NMR) spectra have been observed for <TEX>$LiMPO_4$</TEX> (M = Fe, Mn) samples, as a promising cathode material of lithium ion battery. Observed <TEX>$^7Li$</TEX> shifts of <TEX>$LiFe_{1-x}Mn_xPO_4$</TEX> (x = 0, 0.6, 0.8, and 1) synthesized with solid-state reaction are compared with calculated <TEX>$^7Li$</TEX> shift ranges based on the supertranferred hyperfine interaction of Li-O-M. Ex situ <TEX>$^7Li$</TEX> NMR study of <TEX>$LiFe_{0.4}Mn_{0.6}PO_4$</TEX> in different cut-off voltage for the first charge process is also performed to understand the relationship between <TEX>$^7Li$</TEX> chemical shift and oxidation state of metals affected by delithiation process. The increment of oxidation state for metals makes to downfield shift of <TEX>$^7Li$</TEX> by influencing the supertranferred hyperfine interaction.

Comparison of particulate trace element concentrations in the North Atlantic Ocean as determined with discrete bottle sampling and in situ pumping

The oceanic geochemical cycles of many metals are controlled, at least in part, by interactions with particulate matter, and measurements of particulate trace metals are a core component of the international GEOTRACES program. Particles can be collected by several methods, including in-line filtration from sample bottles and in situ pumping. Both approaches were used to collect particles from the water column on the U.S. GEOTRACES North Atlantic Zonal Transect cruises. Statistical comparison of 91 paired samples collected at matching stations and depths indicate mean concentrations within 5% for Fe and Ti, within 10% for Cd, Mn and Co, and within 15% for Al. Particulate concentrations were higher in bottle samples for Cd, Mn and Co but lower in bottle samples for Fe, Al and Ti, suggesting that large lithogenic particles may be undersampled by bottles in near-shelf environments. In contrast, P was 58% higher on average in bottle samples. This is likely due to a combination of analytical offsets between lab groups, differences in filter pore size, and potential loss of labile P from pump samples following misting with deionized water. Comparable depth profiles were produced by the methods across a range of conditions in the North Atlantic.

Mn Related Defect Levels in Germanium

1. Introduction. Mn doped germanium was studied almost 60 years ago by means of Hall effect [1] and photo conductivity [2] measurements. Based on the temperature dependence of the resistivity and carrier concentration, two levels, one at 0.37eV from the conduction band and one at 0.16eV from the valence band have been assigned to Mn impurities[1]. In agreement with the valence bond model and similar observations by counterdoping with donors for Fe, Co and Ni, these impurities have been assigned to double acceptors. Moreover, the presence of a double acceptor level was confirmed by the observation of the Mn2- state with Electron Paramagnetic Resonance (EPR). [3] However it was also noted in the early studies that the presence of contamination with acceptor impurities may cast doubt on the charge transition assignment. Since the availability of Deep Level Transient Spectroscopy (DLTS), which is a more reliable technique to study deep levels in semiconductors, the electronic properties of most of the 3d transition metals have already been studied with a higher energy resolution. Metal in-diffusion was successful to introduce Cu and Ni[4]. More recently the defect levels of Ti, Cr, Fe and Co have been identified with DLTS on metal-implanted Ge [5,6]. The present study reports on results obtained on Mn doped Ge. 2. Experimental conditions. The source material are single crystal germanium wafers, supplied by Umicore, with a shallow dopant concentration of 1014 cm-3 Ga and Sb for p- and n-type, respectively. To introduce Mn impurities, 99.995% pure Mn was thermally evaporated on the Ge surface. Afterwards the specimens were placed in a resistive furnace under Ar atmosphere for 10 minutes at 700°C. Finally, the residual Mn on the surface was removed by etching with a mixture of HNO3 and HF (3:1?). Schottky diodes for DLTS were prepared by evaporation of Au (n-type) or In (p-type) barriers immediately after etching. To identify the contamination introduced during the processing, Schottky diodes were also prepared on parts of the specimens outside the Mn covered areas. Schottky diodes on n-Ge were also prepared by annealing the n-Ge:Mn samples (after indiffusion at 700°C) to 400°C for 20 min in order to form a MnGe metallic alloy contact. 3. Results and discussion. Fig. 1 a shows the DLTS spectrum of n-Ge:Mn with a MnGe Schottky contact. A similar spectrum was recorded on the specimen with an Au-Schottky barrier. Conventional DLTS shows one electron trap (Mn-E1), while injection of minority carriers (Vp>0) reveals two additional levels (Mn-H1 and Mn-H2). Fig. 1 b shows the DLTS spectrum of p-type Ge, with presence of Mn-H1 and Mn-H2 only after Mn diffusion.Figure 1: DLTS spectrum of a) n-Ge/MnGe diode. b) p-type Ge with and without Mn-difussion. The electron trap Mn-E1 (E=0.36eV) and the hole trap Mn-H1 (E=0.14eV) correspond with the two levels reported before [1,2]. The Mn-H2 peak (E=0.34eV) has to our knowledge not been reported before in the context of transition metal impurities. Nonetheless, its appearance only in Mn diffused samples, its almost equal amplitude and concentration profile to Mn-H1 suggests that it is also related to substitutional Mn in Ge. This may indicate that the substitutional Mn defect can adopt 4 charge states in Ge, one of which certainly corresponds with 2-, as identified with EPR. 4. Conclusions. Three Mn related defect levels have been identified with DLTS. The striking similarity with previously published results for two of the observed levels suggest the assignment to substitutional Mn in germanium. The third level was not reported before but can most probably also be assigned to Mn.