LONG-TIME TEMPERATURE DRIFT IN A COMMERCIAL SQUID MAGNETOMETER

Temperature-calibration measurements using a Pt thermometer placed int o a commercial SQUID magnetometer (Quantum Design) instead of the samp le have shown a long-time(greater than or equal to 8 h) temperature dr ift occurring in a SQUID body. It is found, that the amplitude of this drift depends on the measuring set temperature. We present also resul ts of the mixed-state magnetic-moment measurements as a function of ti me and field performed on Bi2Sr2Ca2Cu3O10 high-T-c superconductor, whi ch illustrate that the magnetometer temperature drift essentially modi fies the true magnetization behavior.