Amorphous Solids : A Review of the Applications of the Mössbauer Effect

Coey, J. M. D.

doi:10.1051/jphyscol:1974608

Cited by 27 publications

(23 citation statements)

References 43 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…Iron-containing silicate glass can be a good candidate for the effective water purification, because dissolving rate and Fe II /Fe III abundance ratio in the glass are easily regulated by changing the composition. Although the structure of iron containing silicate glass has widely been studied by using Mö ssbauer spectroscopy [8][9][10], the relationship between the structure and water purifying ability has not been investigated.…”

mentioning

confidence: 99%

Corelationship between local structure and water purifying ability of iron-containing waste glasses

et al. 2006

View full text Add to dashboard Cite

A relationship between the structure and water purifying ability of waste glass prepared from household garbage and Fe 2 O 3 was examined by 57 Fe-Mö ssbauer and induced coupled plasma (ICP) measurements. From the Debye temperature of waste glass, Fe II proved to be loosely bound in the glass network as a network modifier. Dissolution amount of Fe III into artificial drain can be controlled from 0.14 to 0.35 mg/l by changing the Fe 2 O 3 content. It proved that chemical oxygen demand (COD) decreases in proportion to the content of Fe III , indicating that iron causes decomposition of organic and phosphorus compounds.Key words 57 Fe-Mö ssbauer spectra . Debye temperature . iron-containing silicate glass . chemical oxygen demand (COD)

show abstract

mentioning

confidence: 99%

Corelationship between local structure and water purifying ability of iron-containing waste glasses

et al. 2006

View full text Add to dashboard Cite

show abstract

“…Some discussion of the magnetic structures of these alloys is also included. Applications of the Mossbauer spectroscopy in amorphous solids have been discussed in two recent reviews [5,6].…”

mentioning

confidence: 99%

MÖSSBAUER SPECTRA OF THE AMORPHOUS ALLOYS DyM₃ (M = Fe, Co, Ni)

Arrese-Boggiano¹,

Chappert²,

Coey

et al. 1976

J. Phys. Colloques

Self Cite

View full text Add to dashboard Cite

Rbum6. -Les alliages amorphes DyM3, M = Fe, Co, Ni, ont kt6 ktudies par spectroscopie Mossbauer de 161Dy et s7Fe, avec dopage au fer si nkessaire. YNi3 dope 57Fe a aussi kt6 inclu dans cette etude. Les resultats sont compares avec ceux obtenus pour les alliages cristallins correspondants. Les champs hyperfins a saturation sur le noyau de fer sont considkrablement plus grands ( -30 %) dans les alliages amorphes et on observe une distribution importante dont la largeur relative est --20 %. On discute Ies raisons qui pourraient expliquer la superioritk du moment du metal de transition dans les alliages amorphes. Les champs hyperfins B saturation sur le noyau de dysprosium sont infkrieurs de 1 % a ceux des alliages cristallins, avec une distribution dont la largeur relative est seulement 1 %. A partir des largeurs de raies dont les positions sont sensibles & l'interaction quadrupolaire, on dkduit que la direction du moment de Dy est fortement corrklke B la direction (alkatoire) de la contribution de rkseau au gradient de champ klectrique. On propose des structures magnktiques dans lesquelles les moments de Dy sont pour l'essentiel distribuks dans toutes les directions a I'intkrieur d'une hkmisphkre tandis que les moments de Fe ou Co sont ferromagnktiques. Le moment de Ni est trks faible.'~bstract. -Amorphous alloys DyM3, M = Fey Co, Ni, have been studied by the 161Dy and 57Fe Mossbauer resonances, doping with iron where necessary. 57Fe-doped YNi3 was also included in the study. Results are compared with those for the corresponding crystalline alloys. Iron hyperfine fields at saturation are considerably greater (-30 %) in the amorphous alloys, and there is a broad distribution whose relative width is -20 %. Possible reasons for a greater transition metal moment in the amorphous alloys are discussed. The Dy hyperfine field at saturation is 1 % less than in the crystalline alloys, with a distribution whose relative width is only 1 %. From the widths of lines whose positions are sensitive to the quadrupole interaction, it is deduced that the Dy moment direction is strongly correlated with the (random) direction of the lattice contribution to the electric field gradient. Magnetic structures are proposed in which the Dy moments are essentially distributed over all directions within an hemisphere while the Fe or Co is ferromagnetic. The Ni moment is very small.

show abstract

“…This type of magnetic ordering is observed for very small clusters with the very large specific surface and is named speromagnetic order ing. 22 A similar type of ordering can be presented sche matically as a fan shaped arrangement of magnetic mo ments of individual atoms directed from the cluster center to its periphery with a uniform change in the magnetic moment direction from 0 to 180° relatively to any distin guished direction. The total magnetic moment corre sponds to the incomplete compensation of particular mag netic moments of atoms for this type of magnetic ordering in the cluster.…”

Section: Resultsmentioning

confidence: 98%

Formation and properties of the nanocluster structure of iron oxides

et al. 2006

View full text Add to dashboard Cite

Nanostructures based on iron oxide clusters 1-300 nm in size were synthesized and studied. Thermodynamic models of nanocluster nucleation resulting in the formation of both primary nanoclusters and nanocluster aggregates with the sizes up to 70-80 nm were consid ered. Models of heat capacity of the nanoclusters were examined, and the twofold increase in the heat capacity of the iron oxide clusters 2-3 nm in size compared to that of the bulk iron oxide samples was found. The size of the primary nanoclusters and the intercluster interaction make it possible to vary the magnetic properties of the nanostructures in a wide range from paramagnetic to magnetically ordered α Fe 2 O 3 -γ Fe 2 O 3 nanostructures with the first order magnetic phase transitions, magnetic twinning, and a strong magnetic field (10 Oe) effect on the magnetization increase at low temperatures.Key words: nanoclusters and nanostructures, nanocluster design, heat capacity, magnetic phase transitions, magnetization, Mössbauer spectroscopy, atomic force microscopy.Nucleation and formation of nanoclusters from the gas phase, solutions, and melts are known and well stud ied processes characterized by critical nucleation sizes. 1,2 Processes of cluster nucleation in the solid phase are much more complicated and less controllable. In this case, topochemical reactions leading to the appearance of a new phase can be used. For homogeneous nucleation, the minimum cluster size is determined by the critical nuclea tion radius, and the maximum radius is determined by diffusion restraint of mobility of components of the new phase formed due to the topochemical reaction. 3 In the case of matrix or template restraint, the minimum and maximum cluster sizes are determined by the nanoreactor sizes. 4 The further growth of clusters, for instance, with the temperature increase, can result in cluster agglomera tion; in this case, the initial weak intercluster interaction characteristic of the minimum critical cluster sizes is re placed by the strong intercluster interaction. 5 Solid phase nucleation also occurs when nanocrystallites are formed from the amorphous phase (metals and alloys, amorphous polymers) upon detonation processes, explosions, etc. 6The formation of nanoclusters and a solid phase nanostructure is very complicated; however, these are the processes that determine the final properties of such nanomaterials as metal alloys, ceramics, glasses, and or ganic polymers. Therefore, it is significant to develop models of nucleation interpreting the change or control of the properties of nanostructures. The model of homo geneous nucleation and agglomeration of iron oxide nanoclusters upon the thermal decomposition of iron oxalate was proposed. 3,5 It was shown that both weakly interacting, virtually separated with the media iron oxide nanoclusters and iron oxide nanoclusters of the initial agglomeration stage are stabilized under certain condi tions. This reaction makes it possible to obtain a wide range of iron oxide nanoclusters with the size from one to severa...

show abstract

Amorphous Solids : A Review of the Applications of the Mössbauer Effect

Cited by 27 publications

References 43 publications

Corelationship between local structure and water purifying ability of iron-containing waste glasses

Corelationship between local structure and water purifying ability of iron-containing waste glasses

MÖSSBAUER SPECTRA OF THE AMORPHOUS ALLOYS DyM₃ (M = Fe, Co, Ni)

Formation and properties of the nanocluster structure of iron oxides

Contact Info

Product

Resources

About

Amorphous Solids : A Review of the Applications of the Mössbauer Effect

Cited by 27 publications

References 43 publications

Corelationship between local structure and water purifying ability of iron-containing waste glasses

Corelationship between local structure and water purifying ability of iron-containing waste glasses

MÖSSBAUER SPECTRA OF THE AMORPHOUS ALLOYS DyM3 (M = Fe, Co, Ni)

Formation and properties of the nanocluster structure of iron oxides

Contact Info

Product

Resources

About

MÖSSBAUER SPECTRA OF THE AMORPHOUS ALLOYS DyM₃ (M = Fe, Co, Ni)