  We designed and fabricated a new type of superconducting quantum interference
device (SQUID) susceptometers for magnetic imaging of quantum materials. The
2-junction SQUID sensors employ 3D Nb nano-bridges fabricated using electron
beam lithography. The two counter-wound balanced pickup loops of the SQUID
enable gradiometric measurement and they are surrounded by a one-turn field
coil for susceptibility measurements. The smallest pickup loop of the SQUIDs
were 1 ${\mu}m$ in diameter and the flux noise was around 1
$\mu{\Phi}_0/\sqrt{Hz}$ at 100 Hz. We demonstrate scanning magnetometry,
susceptometry and current magnetometry on some test samples using these
nano-SQUIDs.
