Can I move a single disk from one esxi to another esxi server?

Assuming that ESXi isn't installed on the disk in question, then yes, you should be able to simply install the disk in the new server. If you don't see it immediately, you may need to go to the Configuration tab for the host and choose "rescan" or "Add Storage". Of course, whatever you do, don't format the existing storage again, or you'll lose the data on it. You will probably have to browse the datastore and add the VMs you want to inventory, but it should be a pretty painless process.

http://serverfault.com/questions/293240/can-i-move-a-single-disk-from-one-esxi-to-another-esxi-server