Faraday Force Magnetometer for High-Sensitivity Magnetization Measurements at Very Low Temperatures and High Fields

A Faraday force magnetometer has been developed for static magnetization measurements at very low temperatures down to 100 mK and in fields up to 9 T. The magnetic force acting on a specimen located in the adiabatic vacuum chamber of a dilution refrigerator is detected by a newly designed load-sensing variable capacitor. Use of a superconducting magnet with gradient coils enables accurate measurement of magnetic moment with a resolution of better than 1×10-7A·m2( 1×10-4emu). An application to magnetization measurements on the heavy-electron antiferromagnet CeB6is presented.