Design and fabrication of prototype piezoelectric adjustable X-ray mirrors

Lynx, a next generation X-ray observatory concept currently under study, requires lightweight, high spatial resolution X-ray mirrors. Here we detail the development and fabrication of one of the candidate technologies for Lynx, piezoelectric adjustable X-ray optics. These X-ray mirrors are thin glass shell mirrors with Cr/Ir X-ray reflective coatings on the mirror side and piezoelectric thin film actuators on the actuator side. Magnetron sputtering was used to deposit metal electrodes and metal-oxide piezoelectric layers. The piezoelectric (Pb0.995(Zr0.52Ti0.48)0.99Nb0.01O3) was divided into 112 independent piezoelectric actuators, with 100% yield achieved. We discuss the fabrication procedure, residual thermal stresses and tuning of the Cr/Ir coating stress for the purposes of stress balancing.