Lorad manufactures sulfides through a variety of methods including:
Homogenous Gas Phase reactions with volatile sulfur precursors:
TiCl4 + H2S → TiS2 Titanium Disulfide, battery cathode material.Particularly useful for transition metal dichalcogenide synthesis; MS2 , where M = Ta, Nb, Hf, Zr, Ti.
Gas -Solid reactions:
H2S+ La2O3 → La2S3, Lanthanum sulfide
H2S + 2YCl3 → Y2S3, Yttrium sulfide
CS2+ MgO → MgS Magnesium sulfide
H2S + CoSO4 → Co9S8, Cobalt Sulfide, phase depends upon temperature Hydrodesulfurization catalyst
H2S+ Ce2(CO3)3 → Ce2S3 red pigment for plastic coloring
Reactions with elemental sulfur:
Cd +S → CdS, Cadmium sulfide, photoconductor
Cu + xS → Cu1.8S, Copper sulfide, glass colorant
Solution Processes:
H2S + Zn(aq) → ZnS(s) , Zinc sulfide, phosphor host lattice, source for closed system vapor transport crystal growth. High index optical coating material. IR window material.
Solvated Elemental Sulfur:
Sx(solv) + 2Cu(2+)aq → Cu2S
Homogeneous Precipitation:
(NH2)2CS + M(n+)(aq) → MnSx (ppt), Thiourea hydrolysis
CH3CS.NH2 + M(n+)(aq) → MnSx(ppt), Thioacetamide hydrolysis
All sulfides that can be precipitated by hydrogen sulfide can similarly be precipitated by the acid or base catalysed decomposition of organosulfur reagents. This process allows us to control particle size and distribution. In some cases, with dielectric constant modification and steric control agents, we can offer nanopowders and spherical monosized powders.
Flux driven reactions:
Sx + Na2CO3 → Na2Sx
Na2Sx + Gd2O3 → Gd2O2S , phosphor host lattice, Tb, Eu activated
Classical method for manufacturing oxysulfide phosphors for cathode ray tubes, Scintillators, up-converters for security and tagging operations and, x-ray phosphors.
Reduction Processes:
H2 + CaSO4 → CaS Component of CaGa2S4:Eu phosphors, suitable for LED Applications. Calcium and strontium thiogallates.
Thermal decomposition of Dithiolato Complexes
In{(C2H5)2NCS2}3 → In2S3, battery, quantum dots, photovoltaic thin film component.
Many dithiolato complexes are volatile and can therefore be employed as thin film chemical vapor deposition sources. Some dithiolato complexes can be employed as aerosols for thin film deposition. It is also possible to decompose appropriate dithiolato compounds in specific solvents to generate nano-particles (Quantum dots) of sulfides such as ZnS, CdS, In2S3. Applications assistance for dithiolato CVD source materials is available.
Non-Aqueous Solvent Routes with metal alkyls and Sulfur precursors:
Ga(C2H5)3 + H2S → Ga2S3, Gallium sulfide
Zn(C2H5)2 + H2S → ZnS, Zinc sulfide. Phosphor, can be doped with Mn or rare earths, Eu, Tb.
Ceramic Method, ( High Temperature Solid State Synthesis):
CaS + La2S3 → CaLa2S4, calcium lanthanum sulfide, infrared window material
SrS + Ga2S3 → SrGa2S4, strontium gallium sulfide, excellent phosphor host lattice
CaS + Al2S3 → CaAl2S4, calcium aluminum sulfide, excellent green phosphor host.
Sulfidized Sol-Gel Derived Precursors:
H2S+ Dry Gel or low fired oxide → Sulfide. Has been used for titanium disulfide, (TiS2 ) synthesis.
In addition to these general procedures, we have developed several proprietary methods and modifications to manufacture speciality sulfides (binary and multinary with specific additives to modify physical characteristics) that are used worldwide in a variety of applications including batteries, luminescent materials for displays, data storage, radiation detection, and an range of security applications.
With our years of expertise, we select the most appropriate process and fine tune it to allow us to achieve the precise purity, stoichiometry, and particle size for the customer’s application. With our expanded production capabilities, we can now offer most of these speciality sulfides in multi-ton quantities. Because these items are custom synthesized for particular customers applications, we may impose a minimum order quantity. In addition to the sulfides listed here, we also manufacturer a large catalog of sulfide materials. We also work with our customers, (always on a strictly confidential basis) to develop new products, and seamlessly implement scale-up procedures to meet their production requirements.