Advances in magnetic smart materials for synchrotron x-ray optics: a progress report on annealing and ultra-thin glass substrates

Magnetic smart materials (MSMs) offer an alternative to the typical piezo-electric actuators currently used to control X-ray optics on beamlines. MSMs, combined with an overcoating of a magnetic hard material, create a deformable mirror that can operate in a power-off mode. The non-reflective side of the mirror is coated with an MSM and the magnetic hard overcoat. The process works by using an electromagnet (EM) to impose a magnetic field in the bilayer of the MSM and the magnetic hard overcoat, causing the mirror to deflect. Once the EM is turned off, the mirror settles into a new shape within minutes, which can remain intact for days. Since the EM is not fixed to the mirror, the exact placement of the magnetic field can be adjusted by relocating the EM. This feature allows for fine-scale adjustments and avoids the “dead pixel” replacement problem common with piezo patches attached to the mirror. Here, we provide a progress report based on laboratory-produced data.