Phase stability of (Fe80Nb6B14)(0.9)Tb-0.1 bulk nanocrystalline magnet

The paper refers to phase stability of the (Fe80Nb6B14)0:9Tb0:1 bulk nanocrystalline alloys prepared using the vacuum suction casting technique. The samples were in the form of rods with diameters d = 2, 1.5, 1 and 0.5 mm. Heating up to 900 K reveals structural changes that occur at temperatures above 680 K (DSC and M(T) measurements). The phase analysis, using Mössbauer spectra, indicates the decrease of Tb2Fe14B and increase of Fe content in the samples after the heat treatment. The most stable is the alloy with d = 1 mm, where the formation of -Fe phase was not observed. The decrease of d causes signi cant hardening i.e. coercive eld increases from 0.57 T to 2.66 T for d = 2 mm and d = 0:5 mm, respectively

Phase structure and magnetic properties of Fe-Nb-B-Pt type of bulk nanocrystalline alloys

The paper refers to magnetic and structure properties of the (Fe80Nb6B14)1xPtx (x = 0:15, 0.3, 0.4 and 0.6) bulk nanocrystalline alloys prepared using the vacuum suction casting technique. The samples were in the form of rods with diameters ranging from 0.5 mm to 1.5 mm. It was shown that the optimal Pt content is x = 0:4 with the coercive eld equal to 0.2 T and maximum energy product jBHjmax = 11:2 kJ/m3. The magnetic properties can be associated with Fe-Pt, Fe and Fe-B phases, depending on the alloy composition

Influence of cooling rate on structural and magnetic properties of (Fe78Nb8B14)1-xTbx alloys

In the presented work we are focused on the influence of cooling rate on structural and magnetic properties of (Fe78Nb8B14)1-xTbx (x = 0.08, 0.1, 0.12) nanocrystalline bulk alloys. The samples were fabricated using the vacuum suction technique with different cooling rates controlled by different sample diameters (from 0.5 to 1.5 mm). The increased Nb content leads to the formation of specific microstructure and allows obtaining ultra-high coercive alloys just after casting without any additional treatment. The coercivity exceeds 8.6 T at the room temperature in case of optimal chemical and preparation conditions (x = 0.12, d = 0.5 mm) and 5.6 T for x = 0.1. The impact of Tb content as well as the cooling rate on magnetic and structural (XRD, SEM, MFM) properties is widely discussed in the context of reduction of rare earths in the RE-based permanent magnets

Influence of transition and rare earth elements on magnetic properties of Fe-Nb-B-M (M = Ni, Ag, Gd, Tb) bulk nanocrystalline alloys

In this work we present magnetic properties of the (Fe80Nb6B14)1xMx (where M = Ni, Ag, Gd, Tb and x = 0:08, 0.16, 0.32) bulk nanocrystalline alloys prepared by making use of mould casting technique. The applied preparation technique is favorable to nanocrystallization of the alloys with mean diameters of crystallites ranged from about 10 nm to 30 nm. Phase identi cation reveals a formation of ternary RE2Fe14B and binary REFe2 phases dependently on the alloy composition. It was found that for the alloys with Ag addition magnetic moment of Fe atom increases from 2.26 B to 3.36 B for x = 0:08 and x = 0:32, respectively. For Ni addition this quantity decreases with increasing x due to appearing of Fe Ni (fcc) phases. For Gd, Tb additions the alloys are ferrimagnetic with compensation composition ranged between x = 0:08 and x = 0:16. The both rare earth alloying additions cause a signi cant magnetic hardening especially in the case of Tb

Microstructural and magnetic characterization of Ni0.5Zn0.5Fe2O4 ferrite nanoparticles

International audienc

Protocol, rationale and design of PEOPLE (Post ExpOsure Prophylaxis for LEprosy in the Comoros and Madagascar): A cluster randomized trial on effectiveness of different modalities of implementation of post-exposure prophylaxis of leprosy contacts

Background: Leprosy is an ancient infectious disease with a global annual incidence that has plateaued above 200,000 new cases since over a decade. New strategies are required to overcome this stalemate. Post-exposure prophylaxis (PEP) with a single dose of Rifampicin (SDR) has conditionally been recommended by the World Health Organization (WHO), based on a randomized-controlled-Trial in Bangladesh. More evidence is required. The Post ExpOsure Prophylaxis for Leprosy (PEOPLE) trial will assess effectiveness of different modalities of PEP on the Comoros and Madagascar. Methods: PEOPLE is a cluster-randomized trial with villages selected on previous leprosy-incidence and randomly allocated to four arms. Four annual door-To-door surveys will be performed in all arms. All consenting permanent residents will be screened for leprosy. Leprosy patients will be treated according to international guidelines and eligible contacts will be provided with SDR-PEP. Arm-1 is the comparator in which no PEP will be provided. In arms 2, 3 and 4, SDR-PEP will be provided at double the regular dose (20 mg/kg) to eligible contacts aged two years and above. In arm 2 all household-members of incident leprosy patients are eligible. In arm 3 not only household-members but also neighbourhood contacts living within 100-m of an incident case are eligible. In arm 4 such neighbourhood contacts are only eligible if they test positive to anti-PGL-I, a serological marker. Incidence rate ratios calculated between the comparator arm 1 and each of the intervention arms will constitute the primary outcome. Discussion: Different trials on PEP have yielded varying results. The pivotal COLEP trial in Bangladesh showed a 57% reduction in incidence over a two-year period post-intervention without any rebound in the following years. A study in a high-incidence setting in Indonesia showed no effect of PEP provided to close contacts but a major effect of PEP provided as a blanket measure to an entire island population. High background incidence could be the reason of the lack of effect of PEP provided to individual contacts. The PEOPLE trial will assess effectiveness of PEP in a high incidence setting and will compare three different approaches, to identify who benefits most from PEP. Trial registration: Clinicaltrials.Gov. NCT03662022. Initial Protocol Version 1.2, 27-Aug-2018

Data for: MnAl(C) alloys, ferromagnetic phase, Mechanical alloying, ab initio calculation

Those are input and output files of the simulation data on the position of C in the tetragonal structure of MnAl performed by Quantum Expresso (QE) package (Quantum-opEn-Source Package for Research in Electronic Structure, Simulation, and Optimization, which contains the core package Plane-Wave Self-Consistent Field (PWscf program

Simulation énergétique des trajectoires d'électrons rapides à travers la matière

A novel simulation for the transfer function of high energy electrons with initial energy $E_0$ ($\rm 5~keV \leq E_0 \leq 15~keV$) based in an energy analysis of each stage of the diffusion, is presented for CEMS (Conversion Electron Mössbauer Spectroscopy). The numerical results are in good agreement with ICEMS (Integral Conversion Electron Mössbauer Spectroscopy) experimental data and with the results of previous simulations.Une nouvelle simulation de la fonction de transfert des électrons d'énergie initiale $E_0$ ($\rm 5~keV \leq E_0 \leq 15~keV$) basée sur une analyse énergétique de chaque étape de la diffusion est proposée pour le CEMS (Conversion Electron Mössbauer Spectroscopy). Les résultats numériques obtenus, sont en bon accord avec les expériences obtenues en ICEMS (Integral Conversion Electron Mössbauer Spectroscopy) et avec les résultats des simulations précédentes

Structural and magnetic properties of iron oxides in co-sputtered granular thin films

Granular Fe-V2O5 thin films with different iron concentrations prepared by means of radiofrequency magnetron co-sputtering technique were investigated by means of X-ray diffraction, Transmission Electron Microscopy and 57Fe Mössbauer spectrometry as a function of iron concentration. A common experimental feature reveals that a percolation-like threshold occurs at around 23−25% atomic Fe. Below such a critical value, the co-sputtering process favours the presence of ultrafine amorphous oxide grains with sizes lower than 10 nm embedded in a vanadium oxide matrix. Above, one clearly observes the presence of fine grains (sizes comprised between 10−100 nm) composed of either hematite or maghemite phases dispersed in the same matrix, the set displaying a magnetic order at room temperature