A process enables growing thick stoichiometric crystalline and preferably IR- transparent optical PCMO material on Si and other substrates. Sputter deposition is carried out in oxygen-free inert gas (e.g., Ar) environment, which helps to prevent decomposition of the PCMO material over the substrate. In the disclosed process, there is no need to add a seed layer prior to PCMO deposition. Moreover, no post-deposition annealing is needed in a high-temperature and high-pressure oxygen furnace, but an anneal provides certain additional benefits in terms of improved transparency at IR wavelengths. Over a long deposition time for a thick PCMO film on the high temperature (≤450°C) substrates, the PCMO deposition is made repeated cycles of deposition of the PCMO material at the high temperature, each deposition cycle being followed by cooling the PCMO-deposited substrate to a substantially lower temperature (