A weak-field magnetometer based on a resonator microstrip transducer with thin magnetic films

A high-sensitivity magnetometer of weak quasi-stationary magnetic fields is developed and investigated. The magnetometer transducer is a microstrip resonator with an active medium from thin magnetic films prepared by magnetron sputtering of a Ni$_{75}$Fe$_{25}$ permalloy target. It is demonstrated that the transducer exhibits the maximum sensitivity not only in the optimal dc magnetic field, but also at the optimal deviation of this field from the rf pump field polarization direction. The magnetometer operates in a wide dynamic range of measured magnetic fields from 10$^{-4}$ to 10$^2$ $\mu$T at frequencies of 10$^{-1}$–10$^5$ Hz.