title: On the Immersion Liquid Evaporation Method Based on the Dynamic Sweep of Magnitude of the Refractive Index of a Binary Liquid Mixture: A Case Study on Determining Mineral Particle Light Dispersion.
abstract: This is a feasibility study of a modified immersion liquid technique for determining the refractive index of micro-sized particles. The practical challenge of the traditional liquid immersion method is to find or produce a suitable host liquid whose refractive index equals that of a solid particle. Usually, the immersion liquid method uses a set of immersion liquids with different refractive indices or continuously mixes two liquids with different refractive indices, e.g., using a pumping system. Here, the phenomenon of liquid evaporation has been utilized in defining the time-dependent refractive index variation of the host liquid. From the spectral transmittance data measured during the evaporation process, the refractive index of a solid particle in the host liquid can be determined as a function of the wavelength. The method was tested using calcium fluoride (CaF2) particles with an immersion liquid mixed from diethyl ether and diffusion pump fluid. The dispersion data obtained were consistent with the literature values thus indicating the proper functioning of the proposed procedure.
authors.affiliation: 1 Oulu Mining School, University of Oulu, Oulu, Finland.|2 Department of Electronics Design, Mid Sweden University, Sundsvall, Sweden.
authors.forename: Ilpo
authors.initials: I
authors.lastname: Niskanen
authors.affiliation: 3 Unit of Measurement Technology (MITY), University of Oulu, Kajaani, Finland.
authors.forename: Jukka
authors.initials: J
authors.lastname: Räty
authors.affiliation: 4 Department of Physics and Mathematics, University of Eastern Finland, Joensuu, Finland.
authors.forename: Kai-Erik
authors.initials: KE
authors.lastname: Peiponen
keywords: Refractive index; evaporation; light dispersion; liquid mixture; modified immersion liquid method; solid particles