摘要:

The characterisation of phase mixtures isolated from low alloyed steels, after conventional and thermomechanical treatment shows the following results using electrochemical characterisation and Moessbauer-Spectroscopy:The information content of the voltammogramms is low compared with the informations from the Moessbauer-Spectroscopy. The application of Moessbauer-Spectroscopy enables both, the investigation of the isolated phases and of the bulk material also.

ISSN:0021-1915    

DOI:10.1080/10256019108622469

出版商:Taylor & Francis Group    

年代:1991

数据来源: Taylor

摘要:

Moessbauer and EPR investigations of heteropolyacides of tungsten and molybdenum with iron as heteroatom were carried out with the aim to get more information on the structure of these types of compounds. Of a special interest were the structures of H5[FeO4W12O36] · 6 H2O, FeH2[FeO4W12O36. 17 H2O and H3[Fe(OH)6Mo6O16] · 4 H2O, compounds which are prepared in a solid state for the first time. The general result is: all compounds investigated are associated to the Keggin or Anderson structure. For all heteroatom lattice sites a distortion of the cubic surrounding postulated in the literature was found. The quantity of the heteroatom anion site distortion is strongly influenced by the kind of the cation

ISSN:0021-1915    

DOI:10.1080/10256019108622470

出版商:Taylor & Francis Group    

年代:1991

数据来源: Taylor

摘要:

By help of perturbed angular correlations (TDPAC) the hyperfine interaction in the spinels CdCr2S4and CdCr2Se4is investigated. Both are semiconductors. In the paramagnetic state the111In (111Cd) probes find a dominating axially symmetric quadrupole interaction. The pure magnetic Cd-interaction in the ferromagnetic state known from NMR investigations is observed only for few probes. Single defects (anion vacacnies) which are responsible for the quadrupole interaction will be movable at higher temperatures and they annihilate with a Se excess. The number of probe – vacancy pairs depends on the implantation method of the In-probes. In the case of Cd-probes unperturbed (cubic) environments are observed.

ISSN:0021-1915    

DOI:10.1080/10256019108622471

出版商:Taylor & Francis Group    

年代:1991

数据来源: Taylor

摘要:

Mixed ferrite NixZn1−xFe2O4was precipitated from a solution containing Ni2+, Zn2+and Fe3+ions in the molecular ratio of 1 : 1: 4. The different aged samples were investigated by X-ray diffractometry and Moessbauer spectroscopy. The substance which was not aged contains β-FeOOH and strongly distorted NiZn ferrite. Ageing leads to the formation of spinel structure. Moessbauer spectra of the aged samples exhibit a typical relaxation shape, which can be explained by occuring of small clusters possessing complete spinel structure.

ISSN:0021-1915    

DOI:10.1080/10256019108622472

出版商:Taylor & Francis Group    

年代:1991

数据来源: Taylor

摘要:

The Fe compounds (Et4N)2{[((TSP) (TSPH)Fe]2suc}3) and K[Fe(TSP) (TSPH)prop] · 3H2O3) were characterized by means of57Fe Moessbauer spectroscopy and magnetic measurements. In the temperature region from 300 to 390 K the Fe(III) of both compounds undergoes a discontinuous transition from low spin state to high spin state, returning only slowly into low spin state after cooling to room temperature. This process causes a hysteresis behaviour of the magnetic values. The spin crossover is connected with a complex isomerization. Moessbauer spectra of the compounds show a significant asymmetry, which can be explained by relaxation effects according to Blume's theory.

ISSN:0021-1915    

DOI:10.1080/10256019108622473

出版商:Taylor & Francis Group    

年代:1991

数据来源: Taylor

摘要:

Wet chemical and Moessbauer spectroscopic investigations of natural Li-Fe micas show relations between the iron distribution, the quadrupole splitting and the Li content. The positive correlation between ferrous quadrupole splitting and Li content found for synthetic Li-Fe micas can be confirmed. A dependence of ferric content on the kind of sample collection is obtained.

ISSN:0021-1915    

DOI:10.1080/10256019108622474

出版商:Taylor & Francis Group    

年代:1991

数据来源: Taylor

摘要:

Electrochemically deposited Fe(–Ni)–P alloys exhibit in the as-deposited state a strong magnetic anisotropy with the easy axis perpendicular to the foil plane. Using57Fe Moessbauer measurements in three transmission directions and an evaluation procedure modified with respect to that reported previonsly, it is shown that the Fe43Ni45P12alloy indeed possesses a pronounced normal orientation of the hyperfine field, i.e. the spontaneous magnetization. Application of an in-plane external field leads to an alignment of magnetic domains in field direction, whereas remanent-state results agree with those in the as-deposited state.

ISSN:0021-1915    

DOI:10.1080/10256019108622475

出版商:Taylor & Francis Group    

年代:1991

数据来源: Taylor

摘要:

Ion exchange chromatography of boric acid was carried out using an anion exchange resin in fluoride and chloride forms in order to investigate the temperature dependence of separation factor (S) for boron isotopes. The results are summarized as follows: For the fluoride form resin system, S− 1 = 1348/T2− 0.0051 (between 5 °C and 35 °C) and for the chloride form resin system, S− 1 = 645/T2− 0.0053 (between 5 °C and 50 °C) where T is the temperature in units of K.

ISSN:0021-1915    

DOI:10.1080/10256019108622476

出版商:Taylor & Francis Group    

年代:1991

数据来源: Taylor

摘要:

For the experimental determination of the H02/K ratio of the constants for prototype thermal diffusion columns from initial state mole fraction measurements there was a lack of sufficiently exact simple evaluation methods for polynary isotopic mixtures.

ISSN:0021-1915    

DOI:10.1080/10256019108622477

出版商:Taylor & Francis Group    

年代:1991

数据来源: Taylor