Our niobium pentoxide has one category: sinter. The product in this picture is sinter granule. Applied in: Filter; HR coating We follow critical manufacture standards, quality assurance, welcome your consultation! Specifications Summary: Niobium pentoxide(Chemical formula: Nb2O5) 1.sinter granule: 1-3mm; 3-5mm 2.Color: black grey 3.Purity: 99.99% 4.Package: 1 KG/ bag 5.Storage: avoid exposure to sunlight & acid keep dry Niobium pentoxide properties: 1.Cas no.: 1313-98-6 2.Density(g/cm3): 4.47 3.Melting point(℃):1530 4.Refractive index at 550 nm: 2.1~2.3 5.Transparency range(μm):0.35~9 6.Evaporation source: E Niobium pentoxide properties: 1.Cas no.: 1313-96-8 2.Density(g/cm3): 4.47 3.Melting point(℃): 1530 4.Refractive index at 550nm: 2.1~2.3 5.Transparency range(μm): 0.35~9 6.Evaporation source: E 7.Applications: filter; HR coating