High-Q oscillator torque magnetometer

We describe a torque magnetometer for use at low temperatures based on a high-Q silicon torsional oscillator. The oscillator is fabricated using standard lithographic techniques from a single-crystal silicon wafer. The sample stage of the oscillator has an area of 0.57 cm² and is suitable for deposition of thin magnetic film samples. Oscillator motion is detected through a capacitance measurement. The small torsion constant of the oscillator combined with a Q $\mathrm{value}{\text{\hspace{0.17em}>10}}^6$ allow detection of magnetic moments as small as ${10}^{\text{−13}}\hspace{0.17em}{\mathrm{A\hspace{0.17em}m}}^{\mathrm{2}}.$ Magnetometer sensitivity is measured using small superconducting open cylinders machined from aluminum.