Probes of the 36 series have three different force modulation mode cantilevers on one side of the holder chip.
The coating consists of a Co layer on the tipside of the cantilever. The Co layer is formed as a polycrystalline film, which allows steady permanent magnetization in the direction of the tip axis. All chips are pre-magnetized at the facility before shipping to end users. In some cases additional magnetization by an arbitrary strong magnet is required, e.g. SmCo or NdFeB.
The Co coating is protected from oxidation by a thin Cr layer, resulting in longer cantilever performance.