Zincblende structure
- SiC moissanite
- ZnSe Zinc_selenide stilleite - 5.42g/ccm - Mohs 5 - (Se is rare)
- α-ZnS zinc sphalerite - 4.2g/ccm . Mohs 3.5 to 4 (soft)
- CdS cadmium_sulfide
- are there other examples also forming pseudo phase diagram islands?
Pseudo phase diagrams surrounding SiC
All the carbon group elmenets can be substitutes.
The heavier ones likely only within bounds.
Like e.g. Lead carbide (combining the biggest and smallest atoms of the group) is not achievable via thermodynamic means.
And it's unclear if even via mechanosynthetic means.
Pseudo phase diagrams surrounding ZnS
Investigating the pseudo phase diagrams that emanate from ZnS
Replacing sulfur:
- Replacing all sulfur with oxygen (above S) likely not work since ZnO (zncite) is hexagonal.
- Replacing all sulfur with selenium (below S) works. thhis gives ZnSe Zinc_selenide (mineral stilleite)
Replacing Zinc:
Below Zinc there is cadmium and mercury both rare and toxic.
- CdS cadmium_sulfide has zinkblende structure => all psuedo polymorphs possible
- α-HgS cinnabarite wants to be trigonal rather than cubic
Rift between pseudo phase diagrams
SiC and ZnS have the same structure but there seems to be an unbridgable rift for pseudo phase diagrams.
With other nonmetals sulfur usually assumes bond order two (like oxygen above) but in ZnS it assumes bond order four.
Cross combining the elements leads to some odd compounds instead of a preserved structure. See:
- CS2 is an (odd) liquid.
- SiS2 is an (odd) polymeric compound.
- Zinc carbide ??? barely any info
- Zinc silicide ??? barely any info
Misc
Also a very simple but different (odd) cubic structure: Cu2O cuprite.
