Hot-pressed Fe²⁺:ZnSe ceramics with powders fabricated via grinding chemical vapor deposition ZnSe polycrystalline

Abstract

In this work, Fe2+:ZnSe powders were prepared by grinding a mixture consisting of high-purity ZnSe obtained via chemical vapor deposition and thermally diffused Fe2+:ZnSe. In this manner, it was possible to avoid the presence of harmful H2Se gases and achieve homogeneous distribution of Fe2+ ions in the synthesis of Fe2+:ZnSe powders. Fe2+:ZnSe transparent ceramics were fabricated by hot-pressing as-obtained powders. Phase structure and microstructural properties of the powders and ceramics were studied via X-ray diffraction and field-emission scanning electron microscopy. As-prepared Fe2+:ZnSe ceramics exhibited dense microstructure with relative density higher than 99%, but few residual micropores were found to be localized at grain boundaries. 1.0-mm-thick Fe2+:ZnSe ceramic sintered at 900 °C showed the best optical transmission, namely ∼63% at 5 µm and ∼69% at 14 µm. Additionally, hot-pressed Fe2+:ZnSe ceramics displayed an absorption peak at around 3 µm. These Fe2+:ZnSe ceramics are promising candidates as mid-infrared laser gain materials.

A Review of Cr2+ or Fe2+ Ion-Doped Zinc Sulfide and Zinc Selenide Ceramics as IR Laser Active Media

“…It is well known that the CVD method allows the synthesis of zinc chalcogenides with excellent characteristics in terms of impurity composition and stoichiometry [99,100]. Therefore, the preparation of powders by mechanical grinding of bulk samples of polycrystalline CVD-ZnS or CVD-ZnSe eliminates many of the above problems associated with methods of synthesis from elements or wet chemistry [101]. However, grinding does not provide the desired particle morphology and narrow particle size distributions [69,71].…”

“…Second, the presence of impurities can increase the non-radiative transition probabilities, reducing the luminescence quantum yield, rais ing the lasing threshold, or making it impossible to achieve population inversion at all Therefore, laser ceramics should have both high structural perfection and chemical purity preferably 99.99% or better; in particular, limited impurities that have electronic transi tions in the laser wavelength range should be at the ppm level or less. To create a laser material, ZnSe or ZnS particles are doped with iron or chromium The introduction of these metals is possible by solid phase diffusion into prepared zinc chalcogenide powders [80,101,105,110] as well as during synthesis [79,80,88,89,111,112] In [57], a powder for subsequent consolidation was obtained by mechanical grinding in an agate mortar of pure ZnSe with a ZnSe-CrSe mixture of different concentrations (0.01 0.03, 0.05, and 0.1 mol%). The particle size did not exceed 10 µm.…”

“…Despite a fivefold increase in pressing pressure compared to the technique of [57], pores and inclusions were found in the Cr 2+ :ZnSe ceramics; the quality of the material did not allow laser generation To create a laser material, ZnSe or ZnS particles are doped with iron or chromium. The introduction of these metals is possible by solid phase diffusion into prepared zinc chalcogenide powders [80,101,105,110] as well as during synthesis [79,80,88,89,111,112]. In [57], a powder for subsequent consolidation was obtained by mechanical grinding in an agate mortar of pure ZnSe with a ZnSe-CrSe mixture of different concentrations (0.01, 0.03, 0.05, and 0.1 mol%).…”

“…Fe 2+ :ZnSe ceramics fabricated from mechanically crushed powders are also shown (Figure 5b). In this case, the particle size varied from 0.7 to 35 µm, with 90% of the particles having a size within 1.06-14.2 µm [101]. In [79], a ZnS powder synthesized by chemical precipitation from an aqueous solution using CH 3 CSNH 2 , Zn(NO 3 ) 2 •6H 2 O, and HNO 3 precursors was used [83,84].…”