We have fabricated and tested integrated magnetometers based on the superconducting quantum interference device (SQUID). The magnetometer consists of two patterned films of YBa2Cu3O7, separated by an insulating layer of SrTiO3. A multiturn input coil was integrated on top of the SQUID, where the misorientation angle in a SrTiO3bicrystal substrate was used to form the grain boundary junctions. The noise spectrum was characterized at 77 K and showed that above 10 Hz the magnetometer sensitivity is limited by a white noise level of around 4×10−5&Fgr;0/Hz1/2. In the 4 mm × 4 mm detection area of the input coil, this translates into a magnetic field sensitivity of 320 fT/ Hz1/2at 100 Hz. Compared to the theoretical value of an optimized SQUID the white noise level of the magnetometer is two times higher. Below 10 Hz the noise is dominated by 1/fnoise mainly due to the critical current fluctuations. ©1995 American Institute of Physics.