2 results about "Phase purity" patented technology

The invention belongs to the field of magneto-optical film materials, and particularly relates to a high-phase-purity Ce-doped iron garnet magneto-optical film and a preparation method thereof. The method comprises the following steps: firstly, depositing a layer of YIG film with the thickness of 50-60 nm on a silicon-based substrate as a seed layer through a film preparation process; then, an amorphous Ce: RIG film with the thickness of 10-15 nm is deposited on the YIG, and an amorphous YIG film with the thickness of 1-2 nm is continuously deposited on the amorphous Ce: RIG film; integrally annealing and crystallizing the two layers of amorphous films; and finally, the magneto-optical material film with the required thickness can be obtained by circulating the process of depositing the two layers of amorphous films and integrally annealing and crystallizing. The multi-time deposition annealing magneto-optical thin film material is used, the phase purity of the Ce: RIG thin film and the Ce < 3 + > content in the thin film are improved, compared with a high-temperature deposition and multi-time deposition annealing process, the thermal budget is lower, substrate oxidation can be effectively avoided, the problems of precipitates and element valence states of the silicon-based polycrystalline magneto-optical thin film are solved, and the yield of the silicon-based polycrystalline magneto-optical thin film is improved. And the method has great significance in preparation of the Ce: RIG thin film with high phase purity.

This invention discloses a method for controlling the phases of a Bi-Te-O ternary system, belonging to the field of two-dimensional semiconductor material preparation technology. Using Bi₂Te₃ and Bi₂O₃ powders as reaction sources, controllable growth is achieved on a mica substrate using CVD. By adjusting the growth temperature and system pressure to construct a pressure-temperature synergistic phase diagram, the growth windows for four different phases—elemental Te, Bi₂Te₃, Bi₂TeO₅, and Bi₂O₂Te—were determined and controlled. By utilizing the modulation of the vapor pressure and chemical potential of the precursors by temperature and pressure, the problem of low phase purity caused by differences in precursor reaction concentration and activity in the ternary system is solved, successfully preparing ultrathin two-dimensional Bi₂TeO₅ crystals with a thickness of 3.0–5.7 nm. The preparation method provided by this invention is simple and highly controllable, offering a new technological paradigm for the large-scale and precise preparation of complex ternary two-dimensional systems.