Abstract: A method is provided for producing an article which is transparent to near-wave IR, mid-wave and Long-wave multi-spectral and IR wavelength in the region of 0.4 ?m to 16 ?m. The method includes the steps of (a) Producing ultra-fine powder of CaLa2S4 via SPLTS process, (b) followed by pretreatment of the ultra-fine powder under inert and reducing gas conditions including H2 or Argon or N2 or H2/H2S, H2S, and mixtures there of (c) followed by sieving the powder in 140 mesh screen and cold pressing the powder at 7000 psi for 7 min. into a disk shaped green body (d) then Cold-Isostatic Pressing (CIP) at 40,000 psi for 5 min in a rubber mold (e) finally sintered article of CaLa2S4 disk of 25.

Abstract: A method is provided for producing an article which is transparent to IR wavelength in the region of 4 ?m to 9 ?m. The method includes the steps of (a) Producing ultra-fine powders of ZnS, (b) followed by pretreatment of the ultra-fine powders under reduced gas conditions including H2, H2S, N2, Ar and mixtures there of (c) followed by vacuum (3×10?6 torr) treatment to remove oxygen and sulfates adsorbed to the surface disposing a plurality of nano-particles on a substrate, wherein said nanoparticles comprise ZnS with ultra-high purity of cubic phase; (b) subjecting the nano-particles to spark plasma sintering thereby producing a sintered ZnS product with IR transmission reaching 75% in the wavelength range of 4 ?m to 9 ?m.

Abstract: A method is provided for producing an article which is transparent to near-wave IR, mid-wave and Long-wave multi-spectral and IR wavelength in the region of 0.4 pm to 16 ?m. The method includes the steps of (a) Producing ultra-fine powder of CaLa2S4 via SPLTS process, (b) followed by pretreatment of the ultra-fine powder under inert and reducing gas conditions including H2 or Argon or N2 or H2/H2S, H2S, and mixtures there of (c) followed by sieving the powder in 140 mesh screen and cold pressing the powder at 7000 psi for 7 min. into a disk shaped green body (d) then Cold-Isostatic Pressing (CIP) at 40,000 psi for 5 min in a rubber mold (e) finally sintered article of CaLa2S4 disk of 25.

Abstract: A method is provided for producing an article which is transparent to IR wavelength in the region of 4 ?m to 9 ?m. The method includes the steps of (a) Producing ultra-fine powders of ZnS, (b) followed by pretreatment of the ultra-fine powders under reduced gas conditions including H2, H2S, N2, Ar and mixtures there of (c) followed by vacuum (3×10?6 torr) treatment to remove oxygen and sulfates adsorbed to the surface disposing a plurality of nano-particles on a substrate, wherein said nanoparticles comprise ZnS with ultra-high purity of cubic phase; (b) subjecting the nano-particles to spark plasma sintering thereby producing a sintered ZnS product with IR transmission reaching 75% in the wavelength range of 4 ?m to 9 ?m.

Abstract: A method is provided for producing an article which is transparent to IR wavelength in the region of 4 ?m to 9 ?m. The method includes the steps of (a) Producing ultra-fine powders of ZnS, (b) followed by pretreatment of the ultra-fine powders under reduced gas conditions including H2, H2S, N2, Ar and mixtures there of (c) followed by vacuum (3×10?6 torr) treatment to remove oxygen and sulfates adsorbed to the surface disposing a plurality of nano-particles on a substrate, wherein said nanoparticles comprise ZnS with ultra-high purity of cubic phase; (b) subjecting the nano-particles to spark plasma sintering thereby producing a sintered ZnS product with IR transmission reaching 75% in the wavelength range of 4 ?m to 9 ?m.

Abstract: A method is provided for producing an article which is transparent to infrared radiation. The method includes the steps of (a) disposing a plurality of nanoparticles on a substrate, wherein said nanoparticles comprise a metal sulfide or a metal selenide; (b) subjecting the nanoparticles to spark plasma sintering, thereby producing a sintered product; and (c) removing the sintered product from the substrate as a self-supporting mass.

Abstract: A method is provided for producing an article which is transparent to visible and infrared radiation. The method includes the steps of forming a green body from a population of nanoparticles; depositing a layer of ZnS powder over the green body, thereby producing a covered green body; and sintering the covered green body, thereby producing a sintered product.

Abstract: A method is provided for producing an article which is transparent to visible and infrared radiation. The method includes the steps of forming a green body from a population of nanoparticles; depositing a layer of ZnS powder over the green body, thereby producing a covered green body; and sintering the covered green body, thereby producing a sintered product.

Abstract: A method is provided for producing an article which is transparent to infrared radiation. The method includes the steps of (a) disposing a population of nanoparticles on a substrate, wherein the population of spherical nanoparticles has a population variance of less than 10% in at least one parameter selected from the group consisting of diameter and maximum dimension; (b) subjecting the nanoparticles to spark plasma sintering, thereby producing a sintered product; and (c) removing the sintered product from the substrate as a self-supporting mass.

Abstract: A method is provided for producing an article which is transparent to infrared radiation. The method includes the steps of (a) disposing a population of nanoparticles on a substrate, wherein the population of spherical nanoparticles has a population variance of less than 10% in at least one parameter selected from the group consisting of diameter and maximum dimension; (b) subjecting the nanoparticles to spark plasma sintering, thereby producing a sintered product; and (c) removing the sintered product from the substrate as a self-supporting mass.

Abstract: A method is provided for producing an article which is transparent to infrared radiation. The method includes the steps of (a) disposing a plurality of nanoparticles on a substrate, wherein said nanoparticles comprise a metal sulfide or a metal selenide; (b) subjecting the nanoparticles to spark plasma sintering, thereby producing a sintered product; and (c) removing the sintered product from the substrate as a self-supporting mass.