Intermetallics with lower density than any of its components

Hi there -
I was thinking about concrete examples of intermetallics with lower density than any of its components (whether stable or metastable
phases).
Know that intermetallics sometimes have lower melting temperatures than any of its components, for instance, in the Mg-Al system, and sometimes higher, for instance, in the Ni-Al system, what could be the implications in terms of a lower density?
I would appreciate your feedback,
Cheers,
P.
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Look at NiGa & CoGa. Both are very similar to NiAl. Both have superlattices with substantial vacancy concentrations.
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I am not sure it is remarkable or not but the fact is that, at least in binary systems, I could not find an intermetallic with lower density than any of its components. Equal to, sure, there are a few, especially in ternary systems, but I could not find it in binary systems.
If you have more information about the Ga6PbTe10 please let me know. Is its density 5.9 g/cm3 exactly (and hence lower than galium's 5.904 g/cm3)?
If you know of a binary intermetallic with the characteristic I mentioned please let me know.
Thanks,
P.
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Thanks, I got the abstract of the paper and sent a message to the author. Even though the calculated density appears to be smaller than that of Ga, the difference is quite small between the intemetallic and Ga.
The other suggestion, i.e., CsAu does not work, it forms very intermetallics (daltonides), and due to the very different densities of their components it would not work, especially in a bcc or B2 structure (which I confirmed by looking at Landolt-Bornstein vol. 5).
I did not look at salts, I am much more interested in a real intermetallic rather than a salt.
Thanks a lot for your feedback,
Cheers,
P.
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The problem with InSb and GaSb is that they are not really intermetallics (are they?)... Altough In and Ga are classified as metallic Sb on the other hand is a semi-metallic element, and the result is more of a semiconductor rather than a metallic alloy. However, according to the definition in the Landolt-Bornstein, an intermetallic is a compound of 2 or more elements which have a strong affinity for each other (not containing B, C, H, N, O, or a halogen - so far so good), but the bond is still metallic in nature (which I guess is not the case of GaSb and InSb).
Now, about TlAu (both elements are indeed metallic and the resulting intermetallics, if existing...). Helas, it does not form intermetallic, only solid solutions and two phase solids, according to Landolt-Bornstein.
Cheers,
P.
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