Abstract
Six phases with structures isomorphous with the iron – chromium sigma phase have been reported in binary alloys of the transition elements of the first long period1–3. In addition, Goldschmidt4 has shown that the phase FeMo, stable between 1,180° and 1,540° C., has the same structure. In the binary system cobalt - molybdenum, a similar phase Co2Mo3 exists between 1,250° and 1,620° C.5; recent work in this Laboratory has shown that Co2Mo3 has a sigma-phase structure. The interplanar spacings of the alloy containing 61 atomic per cent molybdenum are very similar to those of the alloy with 50 atomic per cent FeMo given by Goldschmidt, except that they are slightly smaller, as might be expected when the slightly smaller cobalt atom replaces iron. Multiplying the Co2Mo3 d-values by 0.981 gives values which agree well with those for FeCr given by Goldschmidt4.
Similar content being viewed by others
Article PDF
References
Wever, F., and Jellinghaus, W., Mitt. K.W. Inst. Eisenforsch., 13, 93 and 143 (1931).
Sully, A. H., and Heal, T. S., Research, 1, 288 (1948).
Pearson, W. B., Christian, J. W., and Hume-Rothery, w., Nature, 167, 110 (1951).
Goldschmidt, H. S., Research, 2, 343 (1949).
Sykes, W. P., and Graff, H. F., Trans. Amer. Soc. Met., 23, 249 (1935).
Sully, A. G., Nature, 167, 365 (1951).
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
SUMMERS-SMITH, D. The Xi-Phase and a New Sigma Phase. Nature 168, 786 (1951). https://doi.org/10.1038/168786a0
Issue Date:
DOI: https://doi.org/10.1038/168786a0
Comments
By submitting a comment you agree to abide by our Terms and Community Guidelines. If you find something abusive or that does not comply with our terms or guidelines please flag it as inappropriate.