Preparation of pure nickel, cobalt, nickel–cobalt and nickel–copper alloys by hydrothermal reduction

The collective electron theory of ferromagnetism is extended to include in the expression for the energy associated with the magnetization a term in the fourth power of the magnetization. A second adjustable parameter, similar to the kθ'/ϵ 0 of the Stoner treatment, is thus introduced. Detailed comparison with experiment of a number of properties of nickel, nickel-cobalt and nickel-copper alloys, is carried out. A high degree of co-ordination of the properties of nickel is obtained by a suitable choice of the two parameters, which are thereby determined within fairly close limits. The temperature variation of electronic specific heat and spontaneous magnetization of nickel is quantitatively covered, as is the magnetocaloric temperature change accompanying changes in external field. The spontaneous magnetization, temperature curves of cubic cobalt and four nickel-copper alloys are similarly covered, and a simple interpretation can be given of the adherence to the law of corresponding states of nickel-cobalt alloys and the deviation therefrom of the nickel-copper alloys. The model accounts qualitatively for the field-magnetization isothermals and for the variation of the magnetocaloric temperature change with magnetization. A detailed examination shows that the differences between theory and observation, where they exist, are due to effects not covered by the collective electron theory. The main discrepancies can be accounted for on the assumption that a small fraction of the volume of the material is made up of groups of atoms of varying size with a Langevin distribution of their magnetic axes. These groups may be called small domains. The problem is complicated by the fact that the field values computed theoretically are critically dependent on the parameters, of which a sufficiently close estimate cannot be made. However, for particular values of both kθ'/ϵ 0 and A a good fit with experiment over a wide temperature range is obtained when it is assumed that the domains are of sizes varying from 10 3 atoms upwards, the largest proportion of domains being of 10 4 to 10 5 atoms, and the volume occupied by such domains probably being much less than 10% of the total volume of material. It is shown that the hitherto unexplained large temperature variation, derived from the experimental results, in the value of —1/ σ (∂ E /∂ σ ) T corresponding to the Weiss molecular field coefficient, is an almost direct consequence of the basic physical premises of the collective electron treatment.

The reaction of 2-butyne with hydrogen catalyzed by nickel, copper, cobalt, iron, and nickel–copper alloys

Canadian Journal of Chemistry ◽

10.1139/v70-345 ◽

1970 ◽

Vol 48 (13) ◽

pp. 2075-2089 ◽

Cited By ~ 6

Author(s):

R. S. Mann ◽

C. P. Khulbe

Keyword(s):

Copper Alloy ◽

Hydrogen Pressure ◽

Copper Alloys ◽

Kcal Mole ◽

Temperature Dependent ◽

Nickel Cobalt ◽

Nickel Copper ◽

Wide Range ◽

Cobalt Iron ◽

Initial Hydrogen Pressure

The reaction between hydrogen and 2-butyne over unsupported nickel, copper, cobalt, iron, and nickel–copper alloys has been investigated in a static constant volume system between 30 and 250 °C for a wide range of reactant ratios. The reaction over metals and their alloys is simple hydrogenation, the early stages being principally a selective production of cis-2-butene with small yields of polymers. The order of reaction with respect to hydrogen was one and independent of temperature. While the order of reaction over cobalt and copper with respect to 2-butyne was zero, it was slightly negative and temperature dependent for nickel and nickel–copper alloys. The selectivity was independent of initial hydrogen pressure for nickel, cobalt, copper and most of the nickel–copper alloys. The overall activation energy for nickel, cobalt, and copper were 9.1, 6.6, 33.5 kcal/mole, respectively. Selectivity and extent of polymerization increased with increasing amounts of copper in the nickel–copper alloy.

Complexes of N-methyliminobis(methylenephosphonic) acid with cobalt, nickel, copper, and zinc

Collection of Czechoslovak Chemical Communications ◽

10.1135/cccc19880987 ◽

1988 ◽

Vol 53 (5) ◽

pp. 987-994 ◽

Cited By ~ 2

Author(s):

Ivan Lukeš ◽

Zdeněk Kváča ◽

Ivor Dominák

Keyword(s):

High Spin ◽

Electronic Spectra ◽

Central Atom ◽

Cobalt Complex ◽

Nickel Complexes ◽

Magnetic Susceptibilities ◽

Cobalt Nickel ◽

Copper And Zinc ◽

Nickel Copper ◽

Cobalt And Nickel

The 1 : 1 cobalt, nickel, copper and zinc complexes of N-methyliminobis(methylenephosphonic) acid, and 1 : 2 cobalt and nickel complexes were prepared. The effect of alkali and alkali earth metals as "external cations" on the crystallization and stoichiometry of solid cobalt complex was investigated. Infrared and electronic spectra and magnetic susceptibilities indicate that cobalt and nickel form high-spin complexes. The coordination sphere of the central atom is formed by a distorted octahedron of the ligand oxygen atoms.

Discontinuous yielding in pure nickel-copper alloys

Scripta Metallurgica ◽

10.1016/0036-9748(75)90172-6 ◽

1975 ◽

Vol 9 (4) ◽

pp. 407-410

Author(s):

R.P. Zerwekh ◽

T.E. Scott

Keyword(s):

Copper Alloys ◽

Pure Nickel ◽

Nickel Copper ◽

Discontinuous Yielding

THE ELECTRICAL RESISTIVITY AND THERMOPOWER OF NICKEL-COPPER ALLOYS

Le Journal de Physique Colloques ◽

10.1051/jphyscol:1974440 ◽

1974 ◽

Vol 35 (C4) ◽

pp. C4-223-C4-226 ◽

Cited By ~ 22

Author(s):

H. M. AHMAD ◽

D. GREIG

Keyword(s):

Electrical Resistivity ◽

Copper Alloys ◽

Nickel Copper

MAGNETIC PROPERTIES OF NICKEL-COPPER AND NICKEL-COBALT ALLOYS

Le Journal de Physique Colloques ◽

10.1051/jphyscol:19888876 ◽

1988 ◽

Vol 49 (C8) ◽

pp. C8-1937-C8-1938 ◽

Cited By ~ 1

Author(s):

D. C. Jiles ◽

T. T. Chang ◽

D. R. Hougen ◽

R. Ranjan

Keyword(s):

Magnetic Properties ◽

Cobalt Alloys ◽

Nickel Cobalt ◽

Nickel Copper

On the Dissolution of Metals in Ionic Liquids 1. Iron, Cobalt, Nickel, Copper, and Zinc

Sustainable Chemistry ◽

10.3390/suschem2010005 ◽

2021 ◽

Vol 2 (1) ◽

pp. 63-73

Author(s):

Jéssica D. S. Vicente ◽

Domingas C. Miguel ◽

Afonso M. P. Gonçalves ◽

Diogo M. Cabrita ◽

José M. Carretas ◽

...

Keyword(s):

Ionic Liquids ◽

Redox Potential ◽

Final State ◽

Iron Cobalt ◽

Influence Of Temperature ◽

Dissolution Reaction ◽

Cobalt Nickel ◽

Iron Metal ◽

Copper And Zinc ◽

Nickel Copper

Ionic liquids are critical reagents for science and technical processes nowadays. Metals are the most used reagents in the industry. It is crucial to have a deeper understanding of how ionic liquids and metals could interact. In this article the interaction of those two families of compounds is accessed. The dissolution (reaction) of metals with ionic liquids is studied, namely the influence of temperature, redox potential, and availability of an oxidant in the process. The final state achieved by the iron metal samples was also addressed by Mössbauer spectroscopy.

Yields of potassium isotopes in high energy bombardments of vanadium, iron, cobalt, nickel, copper and zinc

Journal of Inorganic and Nuclear Chemistry ◽

10.1016/0022-1902(65)80148-8 ◽

1965 ◽

Vol 27 (12) ◽

pp. 2493-2505 ◽

Cited By ~ 16

Author(s):

K.F. Chackett

Keyword(s):

High Energy ◽

Iron Cobalt ◽

Cobalt Nickel ◽

Copper And Zinc ◽

Nickel Copper ◽

Vanadium Iron

Overlapping energy bands and the theory of collective electron ferromagnetism

Mathematical Proceedings of the Cambridge Philosophical Society ◽

10.1017/s0305004100028115 ◽

1953 ◽

Vol 49 (1) ◽

pp. 115-129 ◽

Cited By ~ 2

Author(s):

A. B. Lidiard

Keyword(s):

Curie Point ◽

Energy Band ◽

Spontaneous Magnetization ◽

Copper Alloys ◽

Implicit Assumption ◽

Energy Bands ◽

Unknown Parameters ◽

Nickel Copper ◽

Predicted Values ◽

A Minor

ABSTRACTThe theory of collective electron ferromagnetism given by Stoner applies to a system of electrons in a single energy band; for iron, cobalt and nickel this is identified with the band of states derived from atomic 3d functions. To bring in the generally assumed overlapping of the 3d band by the wide 4s band in these metals, the theory has been extended to take account of the transfer of electrons from 3d to 4s states with change of temperature. A previous calculation of this transfer effect must be regarded as inadequate, for the part played by the exchange energy in determining the distribution of electrons between the two sets of states was omitted. The general equations are derived in § 2 and used as a basis for discussion of the properties of nickel-copper alloys at absolute zero in § 3. In §§4 and 5 numerical results are presented which show the effect of the overlapping 4s band on the magnetic properties of a system such as nickel both above and below its Curie point. Comparison with the measured paramagnetic susceptibility of pure nickel above the Curie point strongly suggests that for this metal the overlapping 4s band has only a minor influence, although in principle the effect could be very large (cf. Fig. 4). This result is not unambiguous, however, because values thus inferred for the two unknown parameters lead to inaccurate predictions below the Curie point. First, the predicted values for the spontaneous magnetization are too small. Secondly, the theory demands that the nickel-copper alloys should only be ferromagnetic below a copper content of about 20 %, whereas experimentally the limit is known to be about 60 %. In conclusion, it is suggested that the implicit assumption of Stoner's theory that the exchange integrals between all pairs of 3d states are equal to one another is a more serious restriction on the theory than the consideration of only a single energy band.