  We report on the fabrication and characterization of microSQUID devices based
on nanoscale vanadium/copper/vanadium Josephson weak links. Magnetically driven
quantum interference patterns have been measured for temperatures in the 0.24 -
2 K range. As magnetometers, these devices obtain flux-to-voltage transfer
function values as high as 450 microV/Phi_0 leading to promising magnetic flux
resolution Phi_N < 3 microPhi_0 / Hz^(1/2), being here limited by the room
temperature preamplification stage. Significant improvements in the flux noise
performance figures, which are already competitive with existing
state-of-the-art commercial SQUIDs systems, are expected either with cryogenic
preamplification or with the adoption of optimized electronic readout stages
based on active feedback schemes.
