Measurement of 1/f noise using a contact-free current-driving scheme

A new method is proposed to measure the 1/f noise of resistance materials without using current driving contacts. Alternating current is induced in a ring-shaped sample by an ac magnetic flux. Good agreement was obtained between data using this method and the conventional four-probe method. The contact-free method is superior for measuring the 1/f noise in those materials upon which ohmic contacts are difficult to form.