In situ neutron powder investigations of cubic stabilized zirconia [Zr0.85Ca0.15O1.85 (CSZ15)] sinter material were performed at room temperature without an applied direct-current electric field and at 1100K with and without an applied field, i.e. lasting ionic current. Experimental conditions (temperature, oxidizing atmosphere etc.) were chosen as close as possible to `working conditions' of zirconia oxygen sensoric devices. To learn about field-induced structural changes and most probable ionic pathways, atomic displacement parameters were derived in the frame of a non-Gaussian Debye–Waller factor formalism for the oxygens. Probability-density-function maps and pseudo-potential (Veff) maps indicate curved diffusion pathways of the oxygens close to the (100) directions. The action of the applied field is to lower the effective potential barriers.