ZIB

Treffer pro Seite

Treffer 1 - 3 | 3 Treffer

Sortierung

Digitale Medien

The Detailed Mechanism of Oxidation of Ni-P Alloys (1999)

Wierzbicka, M. ; Malecki, A.

Springer

Journal of thermal analysis and calorimetry 55 (1999), S. 981-987

zur Merkliste hinzufügen auf der Merkliste

Details

ISSN: 1572-8943

Schlagwort(e): nickel phosphates ; nickel phosphides ; Ni-P alloys ; oxidation

Quelle: Springer Online Journal Archives 1860-2000

Thema: Chemie und Pharmazie

Notizen: Abstract DTA in conjuction with X-ray diffraction analysis with a high-temperature camera and infrared spectroscopy was employed to determine the mechanism of oxidation of Ni-P alloys. Amorphous Ni-P powders were obtained from a nickel(II) sulphate bath as a nickel source and sodium dihydrophosphate(I) as a reducing agent. The crystallization product is composed of two phases: (f.c.c.) Ni and (b.c.t.) Ni3P. The amorphous to crystalline transformation takes place in the temperature range 280–330°C. Ni3P samples were heated from room temperature to 1050°C in air atmosphere at 5°C min−1. It was found that the first stage of oxidation of Ni3P goes through the intermediate phase of Ni12P5 formation to Ni2P. Some exothermic reactions were observed. Heating runs were interrupted after each reaction for crystal structure determination by IR spectrometry. Infrared spectra are reported and it is shown that the structure units present in the amorphous products at about 700°C were the oxoanions PO3 − and P2O7 −. The final products of the oxidation process are NiO and Ni3(PO4)2.

Materialart: Digitale Medien

URL: http://dx.doi.org/10.1023/A:1010106506249

Permalink

Bibliothek	Standort	Signatur	Band/Heft/Jahr	Verfügbarkeit

Andere fanden auch interessant ...

Artikel (Nationallizenzen)

Volltext

Digitale Medien

Another Approach to the Modified Zhuravlev Equation on the Basis of the Oxidation of V2O4 and V6O13 (1998)

Małecki, A. ; Prochowska-Klisch, B. ; Gajerski, R.

Springer

Journal of thermal analysis and calorimetry 54 (1998), S. 25-34

zur Merkliste hinzufügen auf der Merkliste

Details

ISSN: 1572-8943

Schlagwort(e): activation energy ; kinetic equation ; oxidation ; vanadium oxides ; Zhuravlev equation

Quelle: Springer Online Journal Archives 1860-2000

Thema: Chemie und Pharmazie

Notizen: Abstract It has been found that the modified Zhuravlev equation, [(1−α)−1/3−1]2=ktn, which describes the kinetics of oxidation of V2O4 and V6O13 in the temperature range 820–900 K and in the oxygen pressure range 1.0–20 kPa, can be derived via the assumption that the changes in the observed activation energy result from the changing contributions of the two diffusion processes controlling the reaction rate. The values of the observed activation energy are in the range 160–175 kJ mol−1 for V2O4 and 188–201 kJ mol−1 for V6O13 in the scope of the experimental oxygen pressures and temperatures and conversion degrees of 0.1–0.9.

Materialart: Digitale Medien

URL: http://dx.doi.org/10.1023/A:1010144213799

Permalink

Bibliothek	Standort	Signatur	Band/Heft/Jahr	Verfügbarkeit

Andere fanden auch interessant ...

Artikel (Nationallizenzen)

Volltext

Digitale Medien

Mechanism of Thermal Decomposition of d-metals Nitrates Hydrates (2000)

Małecki, A. ; Gajerski, R. ; Łabuś, S. ; [weitere]

Springer

Journal of thermal analysis and calorimetry 60 (2000), S. 17-23

zur Merkliste hinzufügen auf der Merkliste

Details

ISSN: 1572-8943

Schlagwort(e): DTA ; EGA ; d-metals ; nitrates ; thermal decomposition

Quelle: Springer Online Journal Archives 1860-2000

Thema: Chemie und Pharmazie

Notizen: Abstract A series of six nitrates(V) hydrates of 4d-metals as well as mercury and cadmium thermal decomposition was examined by DTA, TG and EGA techniques. It was found that thermal decomposition of d-metals nitrate(V) hydrates proceeds in three stages: partial dehydration, oxo-nitrates and hydroxide nitrates formation and metal oxides formation. General chemical equations for all decomposition stages were proposed. It was found that dehydration of hydrated salts is accompanied by partial decomposition of nitrate(V) groups.

Materialart: Digitale Medien

URL: http://dx.doi.org/10.1023/A:1010155931266

Permalink

Bibliothek	Standort	Signatur	Band/Heft/Jahr	Verfügbarkeit

Andere fanden auch interessant ...

Artikel (Nationallizenzen)

Volltext

Treffer 1 - 3 | 3 Treffer