What makes cobalt oxide (co3o4) a magnetic material?

[Rzbs]

TL;DR

Which compunds of cobalts are magnetic?

We know cobalt is a magnetic material, it can attracted by magnet. Now if we want to know for example cobalt oxide (co3o4) has magnetic property or not what we should do? I mean is there a role to know bonding of cobalt with which elements results in magnetic property? or is there any online website that list all kind of magnetic materials with details?

 

[Baluncore]

Now if we want to know for example cobalt oxide (co3o4) has magnetic property or not what we should do?

Start with wikipedia, look at the references, then google for details.
https://en.wikipedia.org/wiki/Cobalt(III)_oxide
http://www.ijmse.net/uploadfile/2016/1228/20161228053702519.pdf