The preparation of TeOx-based optical recording media by coevaporating Te02 and Te and by reactive sputtering of Te is reported. The composition of the reactively sputter-deposited TeOx film is found to depend linearly on the 02 partial pressure used. Like the coevaporated films, these films are amorphous as deposited and are a mixture of Te and Te02 Both oven and pulsed-laser annealing tend to induce substantial optical property changes in these films. The temperature at which this optical property change occurs during oven annealing was found to increase with increasing x value of the film. For the laser-annealed films, the optical reflectivity was found to increase slowly even after laser irradiation, not reaching a plateau value until several minutes later. The optical property changes are attributed to the amorphous-to-crystaliine phase transformation and to the segregation of Te from the Te02 matrix and the gradual growth of these segregated Te crystallites after annealing. The effects of the number of nuclei and defects in the films on the Te crystal growth after laser annealing are also reported. © 1986, American Vacuum Society. All rights reserved.