@freemo The style of chart you're looking for is an Ashby chart. With some google-foo, the closest flavor of Ashby chart to what you want I could find publicly available is this:
@freemo The relation between diffusivity (a) and specific heat (Cp) is:
a = k / (rho * Cp)
where k is conductivity, rho is density. So the X axis in this chart is inversely proportional to Cp, but also proportional to k (the y-axis!). The 45 degree dashed lines in the chart are isometric to volumetric specific heat.
This actually answers what I suspected and wanted to answer. I was wondering if the chart would be nice and well ordered (and if so in what way) or just a random jumble with no real relationship... IT is interesting to see that like I suspected there is indeed a close correlation/pattern relating the two across materials.
I was also thinking how some material with really high specific heat capacity and high conductivity would be a very special thing to have, since you can store a lot of energy in it and get that energy out quickly, which in term of energy dynamics is a bit of a holy grail (like in electronics you tend to get one or the other and not both)
@freemo Not too many free lunches in nature. From this chart, the only way to get off the line common to all materials is structural - making a foam out of it. Not really an analog that can push you in the opposite direction, above the line.
Actually now my brain is spinning... it would be super cool where neutronium/neutron star core material, would fall on a chart like this.
Sadly i have yet to find any of that on ebay, but ill keep it on my watchlist ;0