ac magnetic field sensors based on thin-film magnetoelectric (ME) devices operating at room temperature have been fabricated. The ME layers consist of a sol-gel derived Pb(Zr0.52Ti0.48)O3 film and a sputter deposited Fe0.7Ga0.3 film on Si cantilevers. The ME coupling is substantially improved by depositing a Pt layer at the interface. The ME coefficient up to 1.81V/Oe cm is obtained at the mechanical resonant frequency of 333 Hz and at dc bias magnetic field of 90 Oe. Clear reduction in the substrate clamping effect is observed as the Si cantilever thickness is systematically reduced down to 35μm.