Quadratic response of the intermediate state to a transverse alternating magnetic field

The response or susceptibility of the intermediate state in a transverse cylinder of indium to a small alternating magnetic field perpendicular to both the static magnetic field and the axis of the cylinder is studied as a function of frequency, size, resistivity and temperature. The response is quadratic as a second harmonic signal is generated in a pickup coil axial to the static magnetic field. At sufficiently low frequencies the quasi-static limit is attained. At intermediate frequencies the signal is eddy-current damped, and at higher frequencies the signal is dependent on the structure of the intermediate state. © 1968 Springer-Verlag.