Investigation of SnO2/B4C multilayer for application near the boron K-absorption edge

Abstract

The interfaces and optical properties of a new SnO2/B4C multilayer pair were investigated. The evolution of SnO2/B4C interfaces was studied by varying the period thickness from 8.50 to 4.10 nm and individual layers’ thicknesses from 6.0 to 1.5 nm. When the SnO2 layer thickness exceeds 2.0 nm, it remains continuous, achieving an electron density close to bulk values (1.83 e− Å−3), and forms smooth interfaces with B4C. However, when the SnO2 thickness is reduced below 2.0 nm, the layer becomes porous, with an electron density of less than 28% of the bulk value, leading to rougher interfaces with B4C. The optical constants for SnO2 derived from reflectivity measurements performed in the vicinity of the boron K-absorption edge are in close agreement with the calculated values.