Quantum Design, Inc.

Stefano Spagna

Michael Bancroft Simmonds

Ronald E Sager

A torque magnetometer employing integrated piezoresistive levers to measure magnetization of very small anisotropic samples. A sample holding platform is cantilevered from the substrate by parallel legs on which piezoresistors have been applied. A Wheatstone bridge, which includes the piezoresistors, is completely integrated on a magnetometer substrate. Specific output connections are made to the electrical conductors of the bridge in a manner to eliminate Hall effect error signals in an alternative embodiment.

Torque magnetometer utilizing integrated piezoresistive levers

A dual capillary inlet cryogenic test chamber having the ability to continuously regulate temperature between about 1.5 K. and 400 K. A controllably heated capillary tube is located in the cryogenic reservoir, spaced from the test chamber and thermally insulated from the cryogen. This capillary tube has a characteristic impedance to fluid flow. A second low temperature, high impedance capillary tube inlet is also in the cryogenic reservoir and is connected between the cryogen reservoir and the test chamber. The combination of a control system with pressure and temperature feedback, combined with the two inlet tubes of different impedance, enables the apparatus to operate continuously and stably at any temperature within its operating range, or to smoothly sweep through any predetermined temperature range.

Growing community of inventors

La Jolla, CA, United States of America

Stefano Spagna