Mössbauer study of the interface of iron nanocrystallites

Balogh, J.; Bujdosó, L.; Kaptás, D.; Kemény, T.; Vincze, I.; Szabó, S.; Beke, Dezső L.

doi:10.1103/physrevb.61.4109

Cited by 46 publications

(47 citation statements)

References 41 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…In spite of these studies, there still remains a lot to be understood about the interfaces in nanocrystalline materials. [24,27,92,[95][96][97] Apart from the difference in the structure of inter-crystalline region, caused by the different processing techniques, there is evidently a marked deviation from the equilibrium state of the lattice structure (crystalline component) of the nanostructured materials as well. Quantitative XRD and Mo¨ssbauer spectroscopy have been used to study the changes from equilibrium condition, in the lattice parameters of the nanometer sized crystallites produced by various synthesis routes.…”

Section: B Synthesis Of Nanocrystalline Alloysmentioning

confidence: 99%

Role of Nanostructure in Electrochemical Corrosion and High Temperature Oxidation: A Review

Mahesh

Raman

2014

Metall Mater Trans A

View full text Add to dashboard Cite

The extremely fine grain size of nanocrystalline (nc) metallic alloys results in significantly different mechanical, electrochemical and oxidation properties as compared to the coarse-grained alloys of the same composition. Although the synthesis and attractive mechanical properties of nanocrystalline materials have been investigated and reviewed in great depth, the high temperature oxidation and electrochemical corrosion of these materials has received limited attention. The difference in the active dissolution and passivation behavior of nc alloys as compared to their microcrystalline counterparts varies for each alloy system. However, a unified theory explaining these phenomena still eludes us. In this context, this article reviews the progress in the electrochemical corrosion behavior of different nanocrystalline alloys, and hence, develops a better understanding of the effect of grain size, composition, interfacial phenomena and selective dissolution on corrosion of nanocrystalline alloys. This review also presents the role of nanometric grain size and the associated increase in grain boundary diffusion on the high temperature oxidation of nc alloys. The attractive possibility of enhanced oxidation resistance at lower alloying additions as compared to the coarse-grained alloys has been discussed. Although the primary focus of the article is on ferrous alloy systems, however, the lead studies on the role of ultrafine grain size in oxidation/corrosion behavior of other alloys systems have also been reviewed.

show abstract

Section: B Synthesis Of Nanocrystalline Alloysmentioning

confidence: 99%

Role of Nanostructure in Electrochemical Corrosion and High Temperature Oxidation: A Review

Mahesh

Raman

2014

Metall Mater Trans A

View full text Add to dashboard Cite

show abstract

“…Ball milling was carried out in vacuum in a vibrating frame hardened-steel single ball vessel [3]. The X-ray diffracto-grams were measured by a Philips X'pert powder diffractometer using CuK α radiation.…”

Section: Methodsmentioning

confidence: 99%

“…In real samples made by different preparation techniques (evaporation, ball milling, etc.) the separation of the surface and bulk properties is not simple because they are influenced by impurities, mixing and disordering of the components [3,4]. In this paper the magnetic properties of ball-milled FeAl will be investigated, where a peculiar magnetic structure consisting of a nonmagnetic volume surrounded by a surface magnetic layer was found [5].…”

Section: Introductionmentioning

confidence: 99%

Magnetic properties of ball-milled FeAl nanograins

Kiss

Kaptás

Balogh

et al. 2004

phys. stat. sol. (a)

Self Cite

View full text Add to dashboard Cite

Ball milled alloys were investigated by X-ray diffraction, magnetic measurements and Mössbauer spectroscopy. No magnetic saturation is observed up to 5 T and neither the magnetization nor the Mössbauer measurements show a well-defined phase transition but a gradual disappearance of the magnetism with increasing temperature. The hyperfine field distributions and the X-ray grain size data enable the identification of Fe atoms with magnetic moments as some atomic layers' thick surface of the nonmagnetic nanometric Fe -Al grains. The unusual magnetic behaviour is attributed to the large magnetic anisotropy of the low dimensional magnetic surfaces.

show abstract

Section: Introductionmentioning

confidence: 99%

“…In fact, compositional information can be derived from Mössbauer data but requires further analysis in combination with other experimental techniques. In fact, the capabilities of Mössbauer spectroscopy to analyze nanoscale systems have been pointed out by different authors [1,2,3,4].For magnetic applications, the reduction of the characteristic microstructural length to nanometer scale leads to outstanding properties. In fact, nanocrystalline microstructures are common to both the hardest [5,6] and the softest magnetic materials known [7].…”

mentioning

confidence: 99%

Extracting the composition of nanocrystals of mechanically alloyed systems using Mössbauer spectroscopy

Blázquez

Ipus

Franco

et al. 2014

Journal of Alloys and Compounds

View full text Add to dashboard Cite

Determining the composition at the nanoscale generally requires the use of experimental techniques such as 3D atom probe or nanoanalysis, which have limited availability, involve high economic cost and, moreover, imply aggressive sample preparations. However, the combination of Mössbauer spectrometry (MS), X-ray diffraction (XRD) and magnetization measurements can supply very detailed information on the average values of composition of tiny elements of the microstructure such as nanocrystals and boundary regions. Unlike nanoscale techniques, those techniques are widely accessible to most of the scientific community and do not require any special sample preparation, especially for powder samples. Two methods are proposed: the first method uses the ratio between the high field contributions to the MS spectra to extract the composition of the nanocrystals and allows us to follow its evolution; the second method uses average values of the hyperfine field and XRD data to study nanocrystalline samples. These procedures have been applied to two FeNb(B) powder samples obtained by mechanical alloying. The proposed procedures can be easily extended to systems containing other isotopes suitable for Mössbauer spectroscopy or to data from nuclear magnetic resonance experiments.Journal of Alloys and Compounds, 610 (2014) 92-99 http://dx.doi.org/10.1016/j.jallcom.2014.04.195 2 IntroductionCompositional and microstructural characterization of materials is a key point to optimize technological properties, to understand the underlying physics and to develop theories and models to go further in Materials Science. This characterization is especially tricky for nanoscale systems, for which the characteristic size to be analyzed can be so small that could apparently be only accessible to nanoprobe techniques (such as high resolution transmission electron microscopy, 3D atom probe, atomic force microscopy, etc.). The presence of irregularities even at such scales implies non simple interpretation of the results. In addition, nanoscale techniques, in general, require costly (economically and in time) sample preparation procedures and limit the explored region to a very small part of the sample (where, artifacts due to the effects of sample preparation might also play a role). Therefore, a very detailed but local information is obtained and it must be extrapolated to the overall system. Unlike these techniques, conventional ones such as X-ray diffraction or Mössbauer spectroscopy can supply average information of a sample with a macroscopic size. These techniques are widely used to identify the phases present in the material and some other structural characteristics such as crystal size, microstrains, lattice parameter, etc. In fact, compositional information can be derived from Mössbauer data but requires further analysis in combination with other experimental techniques. In fact, the capabilities of Mössbauer spectroscopy to analyze nanoscale systems have been pointed out by different authors [1,2,3,4].For magnetic appli...

show abstract

Mössbauer study of the interface of iron nanocrystallites

Cited by 46 publications

References 41 publications

Role of Nanostructure in Electrochemical Corrosion and High Temperature Oxidation: A Review

Role of Nanostructure in Electrochemical Corrosion and High Temperature Oxidation: A Review

Magnetic properties of ball-milled FeAl nanograins

Extracting the composition of nanocrystals of mechanically alloyed systems using Mössbauer spectroscopy

Contact Info

Product

Resources

About