REVIEW OF THE ELECTRONIC SPECIFIC HEAT OF B.C.C. AND F.C.C. SOLID SOLUTIONS OF FIRST LONG PERIOD TRANSITION ELEMENTS
A review is given of the electronic specific heat vs. electron concentiation for b.c.c. solid solutions, including new data for the systems V-Cr and Ti-V. The latter alloys show a maximum of gamma at approximately 60% V. The electronic specific heat coefficients correlate well with the superconductive transition temperatures, according to the Bardeen-Cooper-Schriffer theory, with an interaction coefficient V independent of composition. It was found that the CsCl-type ordered alloys in the ternary TiFe-TiCo and TiCo-TiNi systems possess electronic specific heat values paralleling those for the b.c.c. Cr-Fe alloys at the same average electron concentrations. The electronic specific heat values for the b.c.c. alloys of transition elements with one another can be apparently described to a surprising extent in terms of a more or less rigid band, the degree of filling up of this band with electrons being determined essentially by the average electron concentration for the alloy. This appears to hold even in cases uhere the electron concentration is determined by averaging over three different atomic species. As found also for the alloy VFe. with a CsCl-type ordered structure, ordering causes little, it any, change in the electronic specific heat values of these alloys. New low temperature specific heat measurements with f.c.c. solid solutions in the Mn-Fe, Mn-Ni, Fe-Ni, V-Ni systems gave coefficients for the specific heat term linear in temperature, which are in some cases quite inconsistent with each other if interpreted as electronic specific heat coefficients. Consistent gamma values were obtained for simple ferromagnetic alloys and for nonmagnetic alloys. For alloys where the simultaneous presence of both ferromagnetic and antiferromagnetic interactions is known from magnetic measurements, or may be considered as very likely, the measured gamma values are anomalously high. It has been proposed by Marshall that a temperature-linear contribution to the low temperature specific heat can arise in instances where a sufficient number of spins are located in a near zero magnetic field. It appears from the results that this condition is often fulfilled in alloys having both ferromagnetic and antiferromagnetic interactions. As a result, in such cases the gamma value measured at low temperatures comprises, in addition to the true electronic specific heat coefficient, also a magnetic component. Using only gamma values obtained for simple ferromagnetic and for norrnagnetic alloys, the shape of the d-band for the f.c.c. solid solutions has been nevertheless successfully determined in the electron concentration range from approximately 8 to 1O. (auth)
- Research Organization:
- Univ. of Illinois, Urbana
- NSA Number:
- NSA-17-016698
- OSTI ID:
- 4724656
- Journal Information:
- Journal de Physique et le Radium (France) Changed to J. Phys. (Orsay, Fr.), Vol. Vol: 23; Other Information: Orig. Receipt Date: 31-DEC-63
- Country of Publication:
- Country unknown/Code not available
- Language:
- English
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Related Subjects
ALLOYS
ALUMINUM
ALUMINUM ALLOYS
ATMOSPHERE
CORROSION
DEFECTS
DIFFUSION
ELECTRON MICROSCOPY
ELECTRONS
FERROMAGNETIC MATERIALS
FILMS
GRAIN BOUNDARIES
HYDROGEN
IMPURITIES
INTERACTIONS
LATTICES
LOW TEMPERATURE
MAGNETIC FIELDS
OXIDES
PRESSURE VESSELS
QUALITATIVE ANALYSIS
REACTION KINETICS
SOLID SOLUTIONS
SPECIFIC HEAT
SPIN
STABILITY
STEAM
SUPERCONDUCTIVITY
SURFACES
TEMPERATURE
TRANSITION METALS
TRANSITION TEMPERATURE
VARIATIONS
WATER
WEIGHT
X RADIATION